Sigma Nutrition Radio

Commonly people are talking about "peptides" to refer to a heterogeneous group of peptide medications or investigational compounds. These are increasingly promoted for injury recovery, tissue repair, performance and longevity, with BPC-157 attracting particular attention.

But what evidence supports the claims made about these compounds? How should animal studies, biological mechanisms and personal anecdotes be interpreted? What is currently known about their safety? And what do recent regulatory discussions actually mean for their medical status and availability?

In this episode, physician and Barbell Medicine founder Dr. Jordan Feigenbaum examines the evidence surrounding BPC-157 and other peptide medications, alongside the wider questions of risk, access and informed decision-making.

[00:13] What we want to address

[04:47] Interview start

[05:29] What do we mean by "peptides"?

[10:32] BPC-157 evidence

[16:49] Sourcing of peptides

[20:19] The gray zone of pro-peptide communication

[24:16] Risk sourcing vs drug effects

[26:25] FDA lists and compounding

[31:05] Risk tolerance and informed consent

[43:02] Why did pharma abandon peptide research?

[47:44] Harm reduction debate

[51:48] Practical takeaways

Most dietary guidelines recommend eating one to two servings of fish per week, often specifying that at least one serving should be oily fish. But how directly is that recommendation supported by evidence? And does adding fish to the diet improve outcomes?

This episode examines where current fish-intake recommendations originated, why findings may appear contradictory, and what substitution analyses can tell us about replacing fish with alternative options.

It also considers evidence from pescatarian and vegetarian cohorts, including whether adding fish would improve an already high-quality diet and whether removing it from a plant-forward diet is likely to provide further benefit.

[00:20] Setting out the question at hand

[03:26] Overview of typical fish intake recommendations

[07:10] Is there good evidence for suggested intakes?

[08:10] Historical context

[13:22] Key evidence: DART trial and cohort data

[19:27] Analysis from Mohan et al.

[25:04] Comparator issue: what is fish replacing?

[30:52] Fish protein vs. plant protein

[44:29] Vegetarian vs. pescatarian cohorts

[55:20] Conclusions

[01:00:50] Key Ideas segment (Premium-only)

Wellness and optimisation culture increasingly presents itself as "science-based". But citing studies, using technical language, or having scientific credentials does not guarantee that the underlying evidence is being represented accurately.

In this episode, exercise science researcher Dr. Nick Tiller, discusses how science can be selectively packaged, overstated, and used to support commercially attractive health claims. It explores the difference between science communication and science commodification, why scientific scepticism is distinct from cynicism, how anecdotes and mechanistic explanations can mislead, and why a single peer-reviewed study should never be treated as definitive evidence.

The conversation also looks further upstream at problems within science itself, including low statistical power, p-hacking, publication bias, questionable research practices, and academic incentives that may favour novelty and positive findings. These issues can then be amplified through media, social platforms, and the wellness industry until tentative findings become confident recommendations.

[03:14] Interview start

[06:22] The health and wellness "lie"

[08:38] Optimization and the illusion of control

[11:14] Science communicators vs commodifiers

[14:21] Vitamin D hype case study

[20:54] Spotting misinformation online

[24:50] Skepticism not cynicism

[28:47] Guidelines for debunking

[33:46] Spotting the grift pattern

[41:25] Bad science in academia

[54:47] Key ideas segment (Premium-only)

Effective athlete support requires more than delivering technically correct nutrition advice. It depends on understanding the athlete's wider environment, anticipating the pressures that disrupt good intentions, and building flexible routines that remain useful across training, competition, travel and everyday life.

This episode explores how practitioners can move beyond rigid prescriptions, use "good, better, best" options, measure meaningful progress, and create environments in which athletes can communicate openly about difficulties. It also examines identity, transitions out of sport, and why sustainable support should develop an athlete's autonomy rather than dependence on the practitioner.

To discuss all this is Gemma McGuinness, registered performance nutritionist, former professional footballer and co-founder of Verus Performance.

[03:48] Nutrition beyond performance

[10:10] Identity and food choices

[18:47] Standards versus perfectionism

[24:52] Planning that actually works

[28:32] Measuring progress in athletes

[33:37] Where discipline can cause problems

[38:40] Building high performance environments

[45:37] Key ideas (Premium-only)

Links:

This episode answers one of the questions raised in the most recent Q&A episode on Sigma Nutrition Premium.

The full episode includes the following questions:

Fiber: Independent effect or proxy for healthy foods? Exposure frequency for matched dose of red meat MTHFR gene mutations and 5-MTHF Typical fish oil supplements vs pharmaceutical-grade products Health impacts of saturated fat in coconut products Do I need to consume whole grains? Could the increasing use of AI pose a threat to doing rigorous science?

To listen to the entire episode (plus the back catalogue of all Premium-exclusive episodes) become a member of Sigma Nutrition Premium.

For episode info and mentioned research go to the episode page here.

Medical screening is often framed as an uncomplicated good: if disease is found earlier, treatment can begin earlier and outcomes should improve.

This episode examines why that reasoning is incomplete. Screening can produce benefit, but it can also generate false positives, incidental findings, overdiagnosis, overtreatment and diagnostic cascades.

Dr. Austin Baraki discusses the distinction between screening people without relevant symptoms and investigating a clinical problem, the probabilistic interpretation of test results, biases that can make screening appear more effective than it is, and the importance of shared decision-making before a test is ordered.

Links:

What does the evidence actually show when we look at plant-based dietary patterns through the lens of food processing? And does classifying foods as "ultra-processed" meaningfully change how we interpret the relationship between plant-based diets and long-term health outcomes?

A recent large prospective cohort analysis examined both healthful and unhealthful plant-based dietary patterns, and importantly, stratified the contributing foods based on whether they were classified as ultra-processed or non-ultra-processed.

In this episode, the study's lead author Dr Alysha Thompson, discusses the many intesresting aspects to the analysis. These include how the dietary indices were constructed, the challenges of applying NOVA classification to self-reported dietary data, the role of residual confounding in observational nutrition research, and the extent to which we can or cannot infer independent effects of processing from these findings.

We also consider the broader implications for the use of processing-based classifications in nutrition science and whether this adds meaningful explanatory value beyond traditional assessments of diet quality.

A common idea is that repeated exposure to sweet taste strengthens our preference for sweetness, which then drives greater intake of sweet foods and drinks. This idea is often used in arguments about fruit, low-calorie sweeteners, diet drinks, and the supposed need to "reset" taste preferences by avoiding sweetness altogether.

But does the evidence actually support that causal chain?

In this episode, Prof. Katherine Appleton, Professor of Psychology at Bournemouth University, discusses what is known about sweet taste exposure, sweet preference, and how these concepts are measured in the scientific literature.

Timestamps:

Links:

In nutrition and health coaching, one of the central challenges is understanding how people actually change, particularly when life is complex, motivation fluctuates, and behaviour is shaped by emotion, identity, environment, and relationships.

In this episode, Dr. Krista Scott-Dixon discusses the human skills that underpin effective coaching practice. We discuss the importance of the coach–client relationship, the role of therapeutic alliance, and how concepts from counselling and psychology can be used appropriately within scope of practice.

The discussion also explores autonomy-supportive coaching, self-regulation, compassion, acceptance, feedback, and the meta-skills practitioners need in order to improve over time.

Links:

Supplement safety is often discussed in very general terms, but in practice the risks depend heavily on the individual. A supplement that is reasonable for one person may be inappropriate for another based on their medications, health conditions, dose, formulation, or the other products they are already using.

This becomes especially important when supplements interact with medications or underlying medical conditions. Some interactions can change how a drug is absorbed, metabolised, transported, or cleared from the body. Others can amplify or oppose the drug's clinical effect, such as increasing sedation, lowering blood pressure or blood glucose, or affecting bleeding risk.

In this episode, Giulia Guerrini, a GPhC-registered pharmacist and researcher at Examine, talks about how clinicians and practitioners can think more systematically about supplement safety, side effects, contraindications, and drug–supplement interactions.

Links:

Electrolytes have become one of the most heavily marketed areas of modern sports nutrition and wellness. What was once a relatively specific tool for certain endurance athletes has increasingly been reframed as an everyday requirement for hydration, energy, focus, productivity, and general health optimisation.

But how much of this messaging is grounded in physiology, and how much is an example of industry taking a real mechanism and extending it far beyond the evidence?

In this episode, we examine why many common use cases are unlikely to require an electrolyte product. Along the way, we explore how wellness marketing, biohacking culture, diet communities, and social media narratives can turn narrow sports nutrition applications into broad claims that many people come to accept as true.

To discuss this topic, Danny is joined by Zoe Rom, a science and environmental journalist, and Kylee Van Horn, a sports dietitian, to discuss how these claims are shaped by marketing, culture, and the attention economy.

Timestamps:

[04:00] Interview start

[07:03] Wellness industry rebrand

[09:16] Electrolytes 101

[16:02] Fear marketing and vague symptoms

[22:50] When athletes actually need them

[28:19] Salt fix and anti science narratives

[33:53] Keto biohacking and identity

[43:42] How to evaluate your need

[48:43] Who should skip electrolytes

Links:

This is a Premium-exclusive episode. Go to the Premium feed to listen. Or subscribe to Premium.

Blood glucose is easy to measure, but not always easy to interpret. This Premium-only episode brings together insights from several previous guests to examine blood glucose responses in more detail.

We discuss the misuse of clinical thresholds, the difference between OGTT results and free-living CGM data, and whether "flatter" glucose curves are actually better in normoglycemic people.

The episode also covers when repeated high glucose excursions may be worth investigating, how sugar intake should be interpreted in context, and why skeletal muscle and exercise play such an important role in glucose regulation.

Overall, the aim is to clarify what glucose responses can tell us, what they cannot tell us, and how to avoid pathologizing normal physiology.

Links:

When considering the health impact of foods, it is important to consider "compared to what?". Increasing the amount of a certain food or nutrient in the diet, typically implies a displacement of another.

While comparisons are more obvious in trials, in epidemiology food substitution models can be useful to help us determine the health effects of increasing/decreasing intake of a food, food group or nutrient.

However, these models are often misinterpreted and miscommunicated as if they are a game of "rock, paper, scissors", where one food beats another, and the losing food must be removed from the diet or considered harmful to health.

In this episode we discuss the problem of treating substitution analyses as food-ranking contests, rather than context-dependent comparisons shaped by the comparator, the unit of substitution, the baseline diet, and the outcome being studied.

Links:

Unprocessed red meat and cancer risk remains one of the most debated topics in nutrition science, partly because the evidence is often presented in overly simplistic terms.

The key question is not whether to adopt a vague "balanced" position on red meat, but whether the evidence clearly identifies intake levels at which colorectal cancer risk increases and whether controlled human trials support plausible mechanisms for that risk.

A second issue is whether claims that fibre, vegetables, or an otherwise "healthy diet" can neutralise high red meat intake are actually supported by the mechanistic evidence, or whether they overstate what dietary context can plausibly offset.

In this episode, Danny and Alan examine the evidence base by moving beyond the usual epidemiology-only debate. They discuss why regional intake patterns and dose thresholds matter, then explore controlled human feeding studies showing how higher red meat intake can increase endogenous N-nitroso compound formation, faecal water genotoxicity, and other mechanistic biomarkers linked to colorectal carcinogenesis.

Links:

Performance nutrition in elite sport is often discussed in terms of meal plans, supplements, and macronutrient targets. However, effective practice in professional environments depends just as much on education, trust, communication, and the ability to translate scientific principles into decisions athletes can act on under real-world constraints.

In this episode, Dr James Morehen discusses his work across elite rugby, football, and combat sports, with particular attention to the demands of professional rugby. The conversation explores how practitioners support athletes in a high-impact collision sport, including fuelling for training and match play, managing body composition without reducing athletes to arbitrary numbers, addressing recovery from muscle damage and injury, and developing practical systems around game-day nutrition.

The episode also provides insight into the realities of building a career in performance nutrition, including the importance of applied experience, interdisciplinary collaboration, and learning how to coach athletes rather than simply prescribe to them.

Links:

Gut health has become a major focus in nutrition, medicine, and consumer wellness, but the term is often used loosely. Claims about microbiome testing, probiotics, fermented foods, fibre, and "boosting" the gut microbiome are now common, yet the evidence behind these claims varies substantially.

In this episode, Dr. Emily Leeming examines what gut health actually refers to, why it cannot be reduced to the microbiome alone, and where current microbiome science is being applied before it is ready. The discussion covers the limits of commercial stool testing, the difficulty of defining a healthy microbiome, and the practical strategies most strongly supported by current evidence.

Links/Resources:

In this episode, we examine what nutrition can realistically do in the condition historically known as PCOS, now renamed polyendocrine metabolic ovarian syndrome, or PMOS.

We begin by explaining why the name change matters: the condition is not defined by ovarian cysts, but is better understood as a broader endocrine-metabolic and ovarian syndrome involving insulin resistance, androgen excess, ovulatory dysfunction, metabolic risk, and psychological burden.

We then assess the nutrition evidence, including energy restriction, weight loss, carbohydrate quality, glycaemic index and load, protein intake, fat quality, appetite regulation, fertility outcomes, and phenotype differences. Rather than seeking a single "PCOS diet", the episode asks which dietary features may plausibly help, how strong the evidence is, and where uncertainty remains.

This is a Premium-exclusive episode. To listen to the full episode, subscribe to Premium.

Body composition goals, particularly bodyfat loss, are among the most common reasons people seek support from a nutritionist or health and fitness professional. While the principles are well established, the challenge is helping individuals apply them consistently in real-world conditions.

Many people struggle due to hunger, unrealistic expectations, emotional eating, inconsistent routines, or overly restrictive dieting approaches. These challenges can make fat loss difficult to sustain, even when someone understands what they "should" be doing.

In this episode, Luke Hanna discusses practical strategies for improving body composition, including food diaries, energy-density manipulation, preloads, mindful eating, and realistic goal-setting. The discussion emphasizes identifying individual barriers, collaborating with clients, and building repeatable behaviours that support both fat loss and long-term maintenance.

Luke Hanna holds a Master's degree in Obesity and Clinical Nutrition from University College London and a degree in Sport and Exercise Science from the University of Portsmouth. He currently works as a nutrition coach and personal trainer.

Timestamps:

Links:

Fasting, nutrient timing, chrono-nutrition, and continuous glucose monitoring are all topics that have generated substantial interest, but they are also areas where exaggerated claims can easily outpace the underlying evidence.

In many cases, tentative hypotheses are presented as if they were already well-established conclusions, despite the fact that the research base is often more mixed and context-dependent than popular narratives imply. It is one thing for an idea to appear biologically coherent. It is another for that idea to translate into meaningful, reliable effects in real-world interventions.

In this episode, Professor James Betts discusses how to think clearly about these topics, why common errors in interpretation can lead to overstated conclusions, and what is required to properly evaluate whether an observed effect reflects a true intervention effect rather than baseline differences, inappropriate comparisons, within-group changes, or mechanistic signals being mistaken for meaningful health outcomes.

Timestamps:

Links:

How should we decide what counts as trustworthy evidence? Scientific rigor is not a single characteristic of a study, but a chain of decisions made from the moment a question is conceived to the point at which findings are communicated to the public.

Errors can occur at every stage: the question may be ill-posed, the design may be incapable of answering it, the measurements may be weak, the analysis may be inappropriate, the interpretation may overreach, and the public-facing communication may become distorted.

In this episode, Dr. David Allison, PhD discusses the deeper methodological issues that shape the field's conclusions. The discussion moves from the philosophy of scientific inquiry to the practical realities of study design, statistical analysis, interpretation, and dissemination.

Links:

Dietary fiber is widely recognized as an important component of a healthy diet, yet it is not typically classified as an essential nutrient. In this episode, Dr. Andrew Reynolds explores whether that distinction still holds, arguing that the traditional criteria used to define essentiality may be outdated when applied to modern nutrition science.

The discussion moves beyond simply acknowledging the benefits of fiber and instead examines whether it meets the foundational requirements of an essential nutrient. This includes considering its physiological roles, the body's inability to synthesize it in sufficient quantities, and whether low intake leads to a meaningful and reversible dysfunction.

Drawing on evidence from prospective cohort studies, randomized controlled trials, and mechanistic research, Reynolds outlines the strength of the evidence linking higher fiber intakes to reduced risk of cardiovascular disease, type 2 diabetes, colorectal cancer, and premature mortality.

Reynolds presents a compelling case that fiber may play a fundamental role in maintaining normal physiological function and therefore warrants reconsideration within the framework of essential nutrients.

Avoidant/Restrictive Food Intake Disorder (ARFID) is an eating disorder diagnosis characterized by a persistent restriction or avoidance of food intake that results in clinically significant consequences (medical, nutritional, and/or psychosocial), but without the weight- and shape-driven psychopathology typical of anorexia nervosa and bulimia nervosa.

In this episode, Megan Hellner and Katherine Hill outline how ARFID presents across the lifespan, why it is frequently missed in routine healthcare, and what an evidence-informed assessment and treatment pathway can look like in practice.

A central theme is that ARFID is not synonymous with "picky eating" and not confined to any one body size. Patients may present at any point on the weight chart, including those who are weight-stable or in larger bodies, and the condition can begin in early childhood and persist into adulthood.

The episode also highlights ARFID in athletes and physically active people, where restricted dietary variety and/or low intake can contribute to low energy availability and RED-S-like presentations, sometimes without an obvious intent to lose weight.

This episode examines what we actually know (and importantly, what we do not know) about diet in relation to gallstones and gallbladder conditions. Much of the public-facing guidance around gallstones focuses on "avoiding fatty foods", yet Dr. Angela Madden explains that this long-standing practice sits on surprisingly weak direct evidence, particularly when judged against the standards typically expected for clinical dietary recommendations.

A central theme is the need to separate two distinct questions: dietary factors that influence the risk of developing gallstones (prevention), versus dietary strategies intended to reduce symptoms or complications once gallstones exist (management). While the prevention literature suggests plausible, consistent associations with overall diet quality and lifestyle factors, the specific question of prescribing a low-fat diet to manage symptomatic gallstones lacks robust randomized trial evidence.

Dr Angela Madden is a clinical researcher in nutrition and dietetics at the University of Hertfordshire, where she established and led the nutrition and dietetics subject group and now focuses her research on improving nutritional assessment, dietary interventions, and patient-centred outcomes in clinical and public health settings.

In this episode, Danny answers questions submitted by Premium subscribers.

[00:05:13] Is eating too early (relative to chronotype) metabolically problematic? [00:16:55] Can plant-based diets reverse cardiovascular disease? [00:32:54] Are multivitamins useful insurance, or a waste with a good diet? [00:44:56] Does coevolution with foods determine human compatibility and benefit? [00:56:25] How should consumers choose supplement formulations and brands? [01:04:46] Folate vs folic acid: differences and best choice for women of childbearing age? [01:12:37] How reliable is omega-3 content in farmed salmon, especially imported frozen salmon? [01:19:18] How accurate are food labels for metabolizable energy and absorption, especially across processing levels? [01:23:58] Protein needs in breastfeeding and general rehabilitation (non-sport injury)?

To listen to the full episode, subscribe to Sigma Nutrition Premium.

"The more we learn about the world, and the deeper our learning, the more conscious, specific, and articulate will be our knowledge of what we do not know, our knowledge of our ignorance. For this, indeed, is the main source of our ignorance — the fact that our knowledge can be only finite, while our ignorance must necessarily be infinite."– Karl Popper

To mark Sigma Nutrition's milestone 600th episode (and 12-year anniversary), Danny and Alan examine several areas in which their views have changed, softened, strengthened, or remained stable over the lifespan of the podcast.

The discussion is therefore not only about nutrition itself, but also about the process of scientific reasoning: how positions are formed, what type of evidence can shift them, and why changing one's mind is often a sign of better thinking rather than inconsistency.

The episode therefore serves as both a review of several specific nutrition controversies and a lesson in scientific epistemology. They discuss topics such as red meat, protein, dietary cholesterol, omega-3s, flavonoids, and sodium.

Links

This episode examines whether unprocessed red meat has a causal role in (1) type 2 diabetes risk and intermediate measures of glucose intolerance (insulin resistance, beta cell dysfunction, glycemic markers) and (2) cardiovascular disease (CVD) risk.

While there is commonly observed risk signal from observational cohorts, there exist short-term randomized controlled trials (RCTs) that show largely null effects on glucose homeostasis. This had led to differing opinions and interpretations of the evidence base.

Some feel that in the context of an otherwise healthy diet, there isn't much to suggest concern about consuming unprocessed red meat. While others are of the view that there does exist a risk and that limiting or even avoiding consumption is prudent.

The crucial concept of replacement effects is discussed. Increasing red meat intake always means decreasing something else or increasing total energy intake. Therefore, interpreting evidence requires specifying the comparator food(s), the background dietary pattern, the dose, the cut (lean vs fatty), and how the meat is prepared.

To discuss their interpretations of this contentious evidence base, Dr. Mario Kratz and Dr. Gil Carvalho join the podcast to go through the studies most directly related to these questions.

This episode examines how exercise and nutrition interact to influence glycaemic control, with particular focus on the postprandial period (i.e., the hours after eating) and on "time-efficient" exercise strategies such as low-volume interval training.

Dr. Jenna Gillen outlines the physiological basis for why muscle contraction can acutely reduce post-meal glucose excursions, why repeated sessions can accumulate into longer-term improvements in insulin sensitivity, and why the nutrition context (pre- and post-exercise feeding, carbohydrate availability, and energy balance) can meaningfully alter observed outcomes.

A key translational thread is that many clinically relevant improvements may come from small, feasible doses of activity; especially post-meal walking and brief "exercise snacks" used to interrupt sedentary time.

However, the discussion considers who these interventions matter for most (and least). Postprandial glucose rises are normal in healthy individuals, whereas reducing exaggerated excursions is most relevant for those with insulin resistance, prediabetes, or type 2 diabetes (T2D).

Dr. Jenna Gillen is an Assistant Professor of Exercise Physiology in the Faculty of Kinesiology & Physical Education at the University of Toronto.

In clinical practice effective nutrition, exercise, and obesity care is rarely about identifying the single "best" plan on paper. Instead, sustainable change depends on behavioral psychology: understanding the person's context, motivation, barriers, and patterns, then co-designing practical steps that can actually be implemented in real life.

David Creel PhD, RD is a clinical psychologist and registered dietitian working in weight management at the Cleveland Clinic. Dr. Creel discusses how clinicians can bridge the gap between "optimal recommendations" and what is most likely to create actual behaviour change. This includes a combination of using collaborative communication, self-monitoring, skill-building, relapse prevention planning, and a multidisciplinary framework.

Behavioral and psychological factors shape food choices, physical activity, and adherence far more than knowing the newest guideline. In addition, the modern obesity treatment landscape (including GLP-1 receptor agonists) increases the need for structured behavior-change support: people may experience new hope and new fear (especially fear of weight regain), and the key clinical question becomes how to use these tools to build durable habits and reduce relapse risk over the long term.

Omega-3 fatty acids (particularly EPA and DHA) have a long history in nutrition and cardiovascular medicine, yet the clinical trial literature is often perceived as inconsistent. This episode examines why some randomized trials show clear benefit while others show null or mixed findings, and how differences in trial design, dose, population risk, and outcome selection can materially change what we observe.

A key theme is separating (1) the persistent cultural narratives around omega-3s (including origin stories that do not hold up well to modern evidence) from (2) the more precise, mechanistic and clinical questions about where supplemental EPA/DHA may reduce cardiovascular risk. The discussion focuses heavily on understanding heterogeneity: why "omega-3 supplementation" is not a single, uniform exposure, and why subgroup patterns (e.g., secondary prevention, higher baseline triglycerides, and higher doses) may explain much of the apparent conflict in the evidence.

Note: This discussion is taken from a previous episode of the podcast. The audio has been remastered and improved, and now study notes and full transcript are available.

Conversations about brain health have been dominated by a competing mix of fatalism and over-promising, with aging framed as inevitable decline and "brain optimisation" sold through weak evidence.

So how should we think about cognition across the lifespan?

In this episode, we explore the idea that neuroplasticity does not disappear in adulthood, but instead continues to respond, for better or worse, to repeated behaviours and exposures. Much of what is labelled age-related cognitive decline may in fact reflect an accumulation of modifiable risk factors.

We also dig into how to critically evaluate brain-health claims and how lifestyle pillars such as exercise, sleep, diet, stress reduction and cognitive training fit into a coherent framework.

The discussion extends to emerging multimodal intervention programs, their promising signals and their clear limitations, and to a broader, multifactorial view of Alzheimer's disease that moves beyond a narrow amyloid-centric model. Finally, we examine the role of genetics, including ApoE4, and why genetic risk does not equate to biological destiny, even later in life.

Dr. Majid Fotuhi is a neurologist and an adjunct professor at the Johns Hopkins Mind/Brain Institute. He earned his medical degree from Harvard Medical School and completed a Ph.D. in neuroscience at Johns Hopkins University. That was followed by internship and neurology residency at Johns Hopkins Hospital.

This is a Premium-exclusive episode of the podcast. To listen to the full episode you need to be subscribed to Sigma Nutrition Premium.

This episode examines dietary fiber through the lens of a practical, clinically relevant question: if higher fiber intakes are consistently associated with reduced chronic disease risk, what intake level should we be aiming for to meaningfully improve health outcomes?

The discussion deliberately spans from common online claims that fiber is "not essential" (and therefore unnecessary), through to mechanistic reasoning and the highest-quality evidence we have for hard outcomes and accepted intermediate cardiometabolic endpoints.

Across the episode, we'll hear from six expert perspectives to integrate epidemiology, controlled feeding studies, and clinical guideline contexts.

We will consider how the dose–response patterns, fiber type/source, individual tolerance, and the limitations of nutrition trials all influence what can be recommended with confidence.

Dr. José Areta and colleagues recently carried out a human intervention study examining how a pronounced, short-term energy deficit interacts with an aerobic training stimulus to shape endocrine, metabolic, and skeletal muscle proteomic adaptations.

The core premise is that "low energy availability" is often discussed in a largely unidirectional risk framework, yet human physiology evolved under intermittent energy scarcity, and therefore adaptive responses may be more nuanced than "energy deficit equals impaired adaptation."

The study used tightly controlled diet and exercise, repeated muscle biopsies, and dynamic proteomic profiling to quantify both abundance and synthesis rates of hundreds of individual muscle proteins. This enables a more granular view of "muscle quality" and phenotype than traditional bulk muscle protein synthesis measures.

The findings were incredibly interesting and could have implications for how we view the impact of energy deficits and exercise response.

We discuss the implications for athletes who routinely encounter transient within-day or multi-day energy deficits, for weight loss contexts, and for broader questions around healthspan and ageing biology.

While the term "hyperpalatable" has been used frequently for considerable time to refer to foods that are so appealing and tasty that they drive overeating, this term hasn't been well-defined nor has there been a universal standard for what it means.

One researcher who set out to create an objective definition for hyper-palatable foods (HPFs) is Dr. Tera Fazzino. Using specific defined thresholds of sugar, fat and salt combinations, Dr. Fazzino and colleagues have looked at the impact of consumption of these HPFs.

In this episode, we delve into defining HPFs and their nutrient profiles, whether they have addictive-like properties, how HPFs differ from (and overlap with) ultra-processed foods (UPFs), the mechanisms by which these foods drive overconsumption, and the broader public health implications.

Tera Fazzino, PhD, is an associate professor of psychology at the University of Kansas. Her research focuses on addiction, obesity, and eating-related behaviors.

In this episode, the discussion turns to a deceptively simple question that sits at the centre of countless nutrition debates: how much protein do we actually need?

On one side, there are confident claims that very high protein intakes are not just beneficial but essential for maximising strength, performance, and muscle mass. On the other, equally strong assertions that the current RDA is entirely sufficient for most people, and that going beyond it is unnecessary or even harmful.

Dr. Eric Helms and Dr. Matthew Nagra work through what the evidence actually tells us when we step away from slogans and thresholds. What does 0.8 g/kg represent, and just as importantly, what does it not? At what point do higher intakes stop meaningfully improving muscle-related outcomes? And where do concerns about kidney function, longevity, and chronic disease fit when we look at long-term data rather than isolated mechanisms?

Rather than treating protein as a single number to defend or dismiss, this conversation places intake in context: training status, ageing, health outcomes, source and optimising for specific goals.

Maintaining the ability to carry out everyday tasks and live independently is often described as a cornerstone of healthy ageing. But what actually happens to muscle strength, power, and functional ability as we get older? And how inevitable is their decline?

At what point do changes in muscle function really begin to matter for day-to-day life? Is loss of strength an unavoidable consequence of ageing itself, or does it reflect something more modifiable? If declines are not fixed, what kinds of training or lifestyle interventions genuinely make a difference, and how strong is the evidence behind them?

In this episode, exercise physiologist Dr Brendan Egan examines these questions through the lens of both epidemiological data and controlled training studies in older adults. What do we learn from short-term resistance training interventions lasting just a few months? Do the gains persist once supervised training ends? And what does this tell us about the practical challenges of maintaining functional capacity over the long term?

The conversation also explores the idea of "use it or lose it" in muscle function, the role of resistance training in extending healthspan, and how exercise programmes can be designed to support independence later in life. Ultimately, the episode asks a simple but crucial question: what does the evidence actually say about staying strong, capable, and functionally independent as we age?

Dr. Brendan Egan is an Associate Professor of Sport and Exercise Physiology the School of Health and Human Performance at Dublin City University. Currently, he is Associate Dean for Research in the Faculty of Science and Health.

Nutrient density refers to the concentration of vitamins and minerals in crops relative to their yield. There are widespread claims that today's fruits, vegetables, and grains contain fewer micronutrients than in decades past, often linked to modern farming practices or soil degradation.

This issue is important because if staple crops become less nutritious, it could silently undermine dietary quality and contribute to micronutrient deficiencies ("hidden hunger") in populations.

Dr. Edward Joy is uniquely qualified to address this topic. As a senior research fellow in food systems and nutrition at Rothamsted Research and an associate professor at the London School of Hygiene & Tropical Medicine, his work centers on the intersection of agriculture and nutrition.

In this conversation, Dr. Joy draws on evidence from agronomy and public health to clarify whether the nutrient content of crops has indeed declined, what factors might be responsible (from soil health to plant breeding and climate change), and what we can do to improve the situation.

The discussion emphasizes an evidence-based perspective on soil nutrients, crop varieties, and interventions, cutting through myths to identify real concerns and practical solutions.

This is a Premium-exclusive episode of the podcast. To listen to the full episode you need to be subscribed to Sigma Nutrition Premium.

Recently we (Danny Lennon & Alan Flanagan) were invited to 'Processing the Evidence', a "behind closed doors" workshop to discuss the latest scientific evidence on the role of processed foods in human health. The event was organized by Professors Ciarán Forde and Vincenzo Fogliano of Wageningen University in the Netherlands.

The workshop attendees included a range of prominent researchers across a range of domains related to food processing, nutrition science, and public health. The sessions included open discussions on current evidence, knowledge gaps and challenges within the UPF debate.

There were several structured sessions looking at different sub-topics, such as:

In this episode, Alan and Danny review some of the key talking points and their takeaways from this event.

This episode explores how asking better questions and using stronger methods can resolve much of the confusion in nutrition science. Dr. Daniel Ibsen discusses why nutrition research often produces conflicting results and how careful methodological thinking can clarify true diet-disease relationships.

Nutrition science has unique challenges – diets are complex, people self-report their food intake imperfectly, and we can't easily run long-term diet experiments on people. Dr. Ibsen explains how embracing concepts like food substitution analysis, the "target trial" framework, and objective dietary assessment can strengthen evidence.

The episode centers on methodological insights that make nutrition research more reliable and actionable. Key themes include defining dietary comparisons explicitly (the "compared to what?" question), considering people's starting diets, and using causal inference techniques to design better studies.

Daniel B. Ibsen is an epidemiologist and nutritional scientist whose work bridges rigorous causal inference methods with real-world diet and cardiometabolic disease research. He is an Associate Professor at Aarhus University, Denmark.

How much do hormonal fluctuations really influence performance and recovery? Should women be adjusting their training and nutrition based on the menstrual cycle? And do female athletes need different protein strategies or recovery protocols than men?

These are questions that have fuelled countless online claims, from rigid "cycle syncing" programmes to supposedly gender-specific nutrition rules. But how much of that is actually grounded in evidence?

In this episode, the conversation tackles those debates head-on, exploring what we truly know about female physiology, adaptation, and recovery, and where confident narratives outpace the science.

You'll hear from four leading experts: Professors Kirsty Elliot-Sale, Stu Phillips, Shona Halson, and Dr. Eric Helms, as they unpack the data on menstrual-cycle variation, autoregulation, and the real determinants of muscle growth and recovery in women.

These discussions were originally recorded live as part of "The Inside Advantage" event hosted by Optimum Nutrition at the McLaren F1 Performance Centre in the UK, where Danny Lennon moderated the session.

This episode centers on the critical gap in nutrition education within medical training and efforts to bridge it. Guest Akash Patel, a medical student who led a pilot nutrition curriculum, discusses why doctors receive little formal training in nutrition despite poor diet being a major driver of disease. With diet-related conditions (obesity, diabetes, cardiovascular disease, etc.) contributing heavily to morbidity and healthcare costs, the conversation highlights a pivotal push to better equip physicians in nutritional knowledge and counseling.

Patel's work comes at a turning point: there are now calls for standardized nutrition competencies in medical education (e.g., a recent JAMA consensus) and a growing recognition that improving doctors' nutrition literacy could enhance patient care and public trust. But at the same time, medical programs already have a huge workload and little space is available for appropriate training. Others state that nutrition shouldn't fall within the remit of doctors. So how do we reconcile all this?

While this episode focuses on the United States context, the concepts apply to other countries, as it outlines both the challenges and the emerging solutions for closing the nutrition training gap in medicine.

Never before has there been greater access to information about nutrition and health. But never before has there been such a low barrier to being seen as an "expert". There are large numbers of people getting information from, and basing their health decisions on, people who don't have direct expertise in the field in which they are talking about.

Moreover, some promote the lack of domain expertise as a feature, not a bug. They claim that those that were conventionally seen as domain experts are either brainwashed, lazy in their thinking, or outright corrupt. And the solution is instead to look to those with a fresh perspective that can illuminate us on the "truth".

In this episode, Alan and Danny discuss this "death of domain expertise", how it plays out online, and its ramifications for people's ability to get good information.

Note: This episode was originally published as an exclusive episode for Sigma Nutrition Premium subscribers. If you wish to get more Premium-only episode or read study notes to our episodes, you can subscribe to Sigma Nutrition Premium.

This is a Premium-exclusive episode of the podcast. To listen to the full episode you need to be subscribed to Sigma Nutrition Premium.

Each year, the conversations on Sigma Nutrition Radio aim to examine the ideas that shape how we understand nutrition, health, and human behavior. This episode brings together the key insights from those discussions, revisiting the most important themes, emerging evidence, and shifts in understanding from the past year.

Across topics such as dietary guidelines, ultra-processed foods, sleep, metabolism, environmental exposures, and the psychology of eating, this review distills what the science actually shows and what remains uncertain.

Whether you have followed throughout the year or are tuning in for the first time, this episode provides a concise synthesis of what truly mattered and what these ideas imply for how we interpret nutrition science moving forward.

We take a look at critical thinking in science and healthcare, examining how we often fall prey to cognitive biases, emotional reasoning, and flawed thinking. Drawing from six different experts in their respective fields, the episode explores why we sometimes believe we are being rational when in fact our conclusions aren't truly evidence-based. The discussion spans what genuine evidence-based practice means, how domain expertise matters, and how factors like identity, beliefs, and emotions can derail objective reasoning.

How should we think about diets that claim to optimise both human and planetary health? Can a single "reference diet" really balance the complex trade-offs between nutrition adequacy, chronic disease prevention, and environmental sustainability?

These questions have gained renewed attention with the release of the 2025 update to the EAT-Lancet Planetary Health Diet. The original 2019 report proposed a mostly plant-based dietary pattern designed to improve population health while staying within planetary boundaries. But since then, new data have emerged—on nutrient requirements, disease risk, and environmental modelling—that complicate many of the original assumptions.

What does the updated evidence actually say about the health impacts of eating in line with this framework? How have the environmental projections changed? And what do these evolving targets mean for individuals, policymakers, and researchers trying to translate broad sustainability goals into practical dietary guidance?

These are some of the questions explored in this episode of Sigma Nutrition, which examines the 2025 EAT-Lancet update, its scientific foundations, and what it reveals about the intersection of nutrition, health, and planetary sustainability.

Ultra-processed foods have become central to the way we eat and to many of the challenges we face in public health nutrition. They dominate supermarket shelves, shape population diets, and often appear as the prime suspect in rising obesity and metabolic disease rates. But beyond the label itself, what exactly makes these foods problematic? Is it their nutrient composition, their texture and palatability, the rate at which we consume them, or the broader environments that make them so accessible and appealing?

The debate around ultra-processed foods sits at the intersection of metabolic science, behaviour, and policy. It raises uncomfortable questions about how food systems evolved to prioritise convenience and profit, and what it might take to meaningfully change that trajectory.

In this episode, Dr. Kevin Hall joins the podcast to examine the evidence from controlled feeding studies and population research, exploring what we really know about ultra-processed foods, overeating, and how we might begin to fix the food environment.

This is a Premium-exclusive episode of the podcast. To listen to the full episode you need to be subscribed to Sigma Nutrition Premium.

What exactly are "antioxidants," and why do they get so much hype? We often hear that blueberries, dark chocolate, and red wine are healthy because they're packed with antioxidants – but is the story really as simple as "more antioxidants = better health"?

In this episode, Danny explores the true role of antioxidants in the body, challenging simplistic narratives. Are antioxidants magic molecules that single-handedly prevent aging and disease? Or is the reality more nuanced, with context and balance being key? We delve into these intriguing questions to clarify what antioxidants are, how they work, and what the current consensus tells us about using them for health.

Antioxidants are frequently credited as the reason why colorful fruits and vegetables are beneficial. Yet, as past Sigma episodes on polyphenols have noted, the benefits of those plant foods aren't primarily due to direct antioxidant effects.

Here we untangle common misconceptions (e.g., "antioxidants = health, always"), distinguish between different types of antioxidants, and explain why simply taking high-dose antioxidant supplements isn't a guarantee of protection – and in some cases might even backfire.

By the end, health professionals and science-savvy listeners will understand the diverse roles of antioxidants, the importance of balance, and how to apply this knowledge in practice.

Links & Resources:

GLP-1 receptor agonists have emerged as a groundbreaking tool in obesity treatment. In this episode, Dr. Spencer Nadolsky (an obesity specialist) explains how these medications are now yielding unprecedented weight loss outcomes in people with obesity.

The discussion centers on GLP-1 agonist drugs like semaglutide and tirzepatide: how they work, how much weight loss they can produce, and why they represent a paradigm shift in obesity management.

Importantly, the conversation addresses practical aspects of using these drugs, including managing their side effects and optimizing patients' diet and lifestyle while on therapy.

This topic is of great significance to nutrition science, clinical practice, and public health. Obesity is a chronic, relapsing condition that has proven difficult to treat with lifestyle changes alone. The advent of GLP-1 agonists offers new hope by inducing weight loss levels previously seen only with surgical interventions.

Understanding these medications is crucial for healthcare professionals: it enables evidence-based prescribing, proper patient counseling on diet and side effects, and integration of medication with lifestyle interventions.

Discussing safety and long-term use is vital, as millions more patients might use these drugs in coming years. From a public health perspective, GLP-1 agonists prompt debates about access and cost, given their high price and life-changing potential.

Public nutrition policy plays a critical role in shaping population health through laws, guidelines, and programs that influence what people eat. In this episode, Emily Callahan, an expert in nutrition policy, talks about why public nutrition policies often fall short and what "success" looks like.

They discuss how evidence-based nutrition interventions can stall due to political or practical barriers, and explore examples ranging from federal food assistance programs to sodium reduction initiatives. Crucially, they address how to evaluate if a policy has worked and highlight emerging strategies (like integrating "food as medicine" into healthcare) that offer hope for better outcomes.

This conversation is highly relevant for researchers, clinicians, and nutrition professionals, as it underscores the importance of policy in addressing nutrition challenges at the population level and examines how to design effective, data-driven policies for public health impact.

Sodium bicarbonate is one of the most consistently supported ergogenic aids in sports nutrition research, yet its underlying mechanisms and real-world applications remain widely misunderstood.

More recent developments have focused on how to optimise both the timing and formulation of supplementation. The "individualised ingestion timing" approach has emerged as a practical strategy, recognising that the time-to-peak blood bicarbonate concentration varies considerably between individuals.

Similarly, novel formulations are being explored to address issues with gastrointestinal distress and practicality of dosing. These include topical approaches such as sodium bicarbonate lotion, and commercial products like Maurten's "Bicarb System."

In this episode, Prof. Lewis Gough joins to discuss the latest evidence on sodium bicarbonate and performance, its mechanisms, novel delivery systems, and the key directions for future research.

Dr. Lewis Gough is a Professor of Nutrition and Physiology at Birmingham City University. He is globally recognized for his research on sodium bicarbonate supplementation in sport, and his work spans applied sport and exercise nutrition, exercise metabolism, acid–base balance, and fatigue.

In this episode, we explore the concept of chronotype, which reflects an individual's biological circadian timing and how it manifests in preferred sleep–wake patterns. Understanding chronotype is important because it differs from simple diurnal preference, which may be shaped by lifestyle or psychological factors rather than biology.

We examine how chronotype is measured, from gold-standard laboratory methods to validated questionnaires used in field studies. The discussion also highlights the importance of accounting for sleep debt when estimating true biological timing. Finally, we consider the limitations of consumer devices and the practical implications of assessing chronotype in real-world settings.

Dr. Chris Melby is a Professor in Food Science and Human Nutrition at Colorado State University. He has a long-standing research focus on the interplay between dietary eating patterns and exercise/physical activity in regard to energy metabolism and positive and negative energy balance.

In recent times Dr. Melby has published work on the relationshop between energy flux and the probability of maintaining a previous loss of body weight. Long-term maintenance of weight loss requires sustained energy balance at the reduced body weight. This could be attained by coupling low total daily energy intake (TDEI) with low total daily energy expenditure (TDEE; low energy flux), or by pairing high TDEI with high TDEE (high energy flux).

This episode is sponsored by Legion Athletics. Get 20% off your order using the code SIGMA. All US order come with free shipping and all international orders have free shipping on orders over $99. All orders have a money-back guarentee. Check out the products at buylegion.com

This episode is a supplemental/follow-up episode to the 'Diet & Cardiovascular Disease' Series of Sigma Statements. If you have not read those statements, you can find them on sigmanutrition.com

his episode is sponsored by Legion Athletics. Get 20% off your order using the code SIGMA. All US order come with free shipping and all international orders have free shipping on orders over $99. All orders have a money-back guarentee. Check out the products at buylegion.com

Sigma Statements: https://sigmanutrition.com/category/blog-post/statements/

Dr. Michael Grandner is the Director of the Sleep and Health Research Program and an Assistant Professor in the Department of Psychiatry in the University of Arizona College of Medicine – Tucson. He is Board-Certified in Behavioral Sleep Medicine.

His research focuses on how sleep and sleep-related behaviors are related to cardiovascular disease, diabetes, obesity, neurocognitive functioning, mental health, and longevity.

He has published over 150 articles and chapters on issues relating to sleep and health and his work has been cited over 2,500 times. He is associate editor of the journal Sleep Health and serves on the editorial boards of the journals SLEEP, Journal of Clinical Sleep Medicine, Sleep Medicine, Behavioral Sleep Medicine, Journal of Sleep Research, and Frontiers in Neurology: Sleep and Circadian Rhythms.

This episode is sponsored by Legion Athletics. Get 20% off your order using the code SIGMA. All US order come with free shipping and all international orders have free shipping on orders over $99. All orders have a money-back guarentee. Check out the products at buylegion.com

Sigma Statements: https://sigmanutrition.com/category/blog-post/statements/

Dr. Samia Mora is an Associate Professor of Medicine at Harvard Medical School, Boston, Massachusetts. She is a cardiovascular medicine specialist at the Brigham and Women's Hospital, where she is the Director of the Center for Lipid Metabolomics. Dr. Mora's research focuses on risk factors and prevention of cardiovascular disease.

Dr. Mora received her undergraduate degree from Harvard University, and her medical degree from Harvard Medical School. She completed an internal medicine residency at Massachusetts General Hospital and a cardiovascular disease fellowship at The Johns Hopkins Hospital, where she also obtained a Masters in Health Science (Epidemiology) from the Johns Hopkins Bloomberg School of Public Health.

This episode is sponsored by Legion Athletics. Get 20% off your order using the code SIGMA. All US order come with free shipping and all international orders have free shipping on orders over $99. All orders have a money-back guarentee. Check out the products at buylegion.com

Sigma Statement: https://sigmanutrition.com/lipids

Dr. Fergus Connolly is one of the world's foremost human performance thought leaders and influencers, and has applied performance science with leading sports, military, and business teams. He is the only coach to have full times roles in every major sport. Fergus has served as Director of Elite Performance for the San Francisco 49ers, Sports Science Director with the Welsh Rugby Union, and Performance Director for University of Michigan Football. He has guided coaches, support staff and players in the NBA, Australian Rules Football and international cricket. Fergus has also trained world boxing champions and advises elite military units and companies across the globe.

This episode is sponsored by Legion Athletics. Get 20% off your order using the code SIGMA. All US order come with free shipping and all international orders have free shipping on orders over $99. All orders have a money-back guarentee. Check out the products at buylegion.com

Dr. Allison Brager is a behavioral neurobiologist with an expertise in sleep and circadian rhythms for the United States Army (active duty), as well as their contributions to psychiatric, neurological, and inflammatory disease states. She is currently the Director of Human Performance Operations and Outreach Education at the US Army Warrior Fitness Training Center in Fort Knox, Kentucky.

Her work has examined sleep and activity regulatory mechanisms as well as adaptation and resiliency to environmental stressors such as exercise, jet lag, and sleep deprivation. She consults with US Olympic, collegiate, and professional sporting teams and major police and fire departments (e.g., NYPD, Boston) in preparation for travel and to create sleep friendly environments.

She has served on the Board of Directors of the Sleep Research Society and presently chair a public advocacy committee for the Society for Research on Biological Rhythms. She previously was a Postdoctoral Fellow at the Morehouse School of Medicine in Atlanta, Georgia, as well as the Chief of the Sleep Research Center at the Walter Reed Army Institute of Research.

This episode is sponsored by Legion Athletics. Get 20% off your order using the code SIGMA. All US order come with free shipping and all international orders have free shipping on orders over $99. All orders have a money-back guarentee. Check out the products at buylegion.com

Dr. Andrew Chappell is a Lecturer/Researcher at Robert Gordon University, conducting research in sports nutrition, with a specific focus on bodybuilding.

Andrew is also a world-class natural bodybuilder with an unprecendented level of national and international success; having 2 Pro Cards and 6 British titles to his name. Andrew also has judged physique contests for over 7 years and has judged at British and World Finals.

Andrew holds a PhD from the Rowett Institute of Nutrition and Health. He also holds a BSc in Sport and Exercise Science and a MSc in Human Nutrition and Metabolism.

This episode is sponsored by Legion Athletics. Get 20% off your order using the code SIGMA. All US order come with free shipping and all international orders have free shipping on orders over $99. All orders have a money-back guarentee. Check out the products at buylegion.com

Dr Meeta Singh is a sleep doctor whose work and research focuses on "coaching the sleep muscle" to help maximize performance in both individual athletes and sports teams.

She is the Service chief of the sleep medicine, and section head and medical director at the Henry Ford sleep laboratory in Michigan.

She did her training in psychiatry at the Mayo clinic and a sleep fellowship at the Henry Ford hospital. She is board-certified by the American Board of Psychiatry and Neurology as a psychiatrist and sleep medicine sub-specialist.

She has served as a consultant for multiple NFL, MLB, NHL and NBA teams. Dr. Singh performs athletic sleep assessments with personalized prescriptions for better sleep. She also helps sports teams and athletes with their travel management with a focus on addressing sleep deprivation and jet lag and maximizing athletic performance.

This episode is sponsored by Legion Athletics. Get 20% off your order using the code SIGMA. All US order come with free shipping and all international orders have free shipping on orders over $99. All orders have a money-back guarentee. Check out the products at buylegion.com

Ciaran O' Regan is currently a strength & conditioning coach in Cork, Ireland, predominantly working with rugby teams. He recently began a Professional Doctorate under John Kiely of University of Central Lancashire.

Ciaran has a BSc. in Sport & Exercise Science from the University of Limerick. Ciaran also works online with combat sport athletes on their nutrition and fight preparation here at Sigma Nutrition.

This episode is sponsored by Legion Athletics. Get up to 30% off your order using the code SIGMA. All US order come with free shipping and all international orders have free shipping on orders over $99. All orders have a money-back guarentee. Check out the products at buylegion.com

Dr. Robin Tucker is currently an Assistant Professor of Food Science & Human Nutrition at Michigan State University.

The Ingestive Behavior Lab at MSU, under Dr. Tucker's direction, examines the biological and environmental factors that influence human feeding practices.She is especially interested in how the chemical senses (taste and smell) and sleep influence food intake, physical activity, and body composition.

Robin is a registered dietitian and has a PhD in Nutrition Science from Purdue University, focusing on Concentration-Ingestive Behavior.

Show Notes: https://sigmanutrition.com/episode308/

Stephan Guyenet is an obesity researcher, neurobiologist, and author. In addition to his research, he enjoys synthesizing and communicating science for a general audience over at his hugely successful blog.

Stephan has a PhD in neurobiology (University of Washington). He is the author of 'The Hungry Brain', which dives into the causes of obesity from the perspective of overeating and related brain chemistry.

He is also the founder of Red Pen Reviews, a site that uses a structured expert review method to deliver the most informative, consistent, and unbiased nutrition/health book reviews available.

Show notes: https://sigmanutrition.com/episode307

Daniel Davey has worked as a performance nutritionist with a host of elite athletes in a range of sports such as golf, athletics, rugby and GAA.

He is perhaps best known for his roles working as a performance nutritionist with with Leinster Rugby and the Dublin senior footballers.

Daniel holds an MSc in Nutrition, Physical Activity & Public Health from the University of Bristol, in addition to a BSc in Science from University College Dublin.

As an athlete Daniel has played Gaelic football at intercounty level for Sligo and won an All-Ireland club football medal in 2016 with Ballyboden St' Enda's in Dublin.

Show notes: sigmanutrition.com/episode306

John Berardi, PhD is best known as the co-founder of Precision Nutrition. He is also the founder of Change Maker Academy, which is devoted to helping people turn their passion for health and fitness into a successful career. Over the last 15 years he has advised Apple, Equinox, Nike, and Titleist, as well as the San Antonio Spurs, Carolina Panthers, US Open Champ Sloane Stephens, and 2-division UFC Champ Georges St. Pierre.

Get a free chapter to John's new book (or pre-order the book) at the show notes page: sigmanutrition.com/episode305

Dr. Tommy Wood is a Research Assistant Professor at the University of Washington in the Pediatrics Department. esearch focuses on ways to increase resilience of, and treat injury of, the developing brain. He studied biochemistry at Cambridge, received a medical degree from Oxford, and has a PhD in physiology and neuroscience from the University of Oslo.

Show notes: https://sigmanutrition.com/episode304

Brad is a trained Exercise Physiologist, Molecular Biologist, and Biostatistician. He completed his a post-doctoral fellowship in translational science at Providence Medical Research Center, where he studied how metabolism and inflammation regulate molecular mechanisms disease and is involved in discovering novel therapeutics for diabetic complications.

His research career has spanned the translational spectrum utilizing basic science, human trials, and machine learning in large data sets to identify and develop novel therapies and technologies.

His long term career goals include leading teams of people to make major inroads in health care through the development of new technology. Brad is also passionate about scientific outreach and bringing science to the public.

Show Notes: https://sigmanutrition.com/episode303

Associate Professor Leonie Heilbronn is the leader of the Obesity and Metabolism group based at the University of Adelaide, Australia.

She has a sustained record of translating basic discoveries in nutrition to humans and has contributed to current concepts of caloric restriction (CR), intermittent fasting (IF) and time restricted eating (TRE) in humans.

She is keenly interested in understanding mechanisms of insulin resistance in skeletal muscle and in adipose tissue utilising nutritional perturbations. She is an Associate Editor of Obesity and Obesity Research and Clinical Practice.

Show Notes: https://sigmanutrition.com/episode302

John Berardi, PhD is best known as the co-founder of Precision Nutrition. He is also the founder of Change Maker Academy, which is devoted to helping people turn their passion for health and fitness into a successful career. Over the last 15 years he has advised Apple, Equinox, Nike, and Titleist, as well as the San Antonio Spurs, Carolina Panthers, US Open Champ Sloane Stephens, and 2-division UFC Champ Georges St. Pierre.

Show notes: https://sigmanutrition.com/episode301

Sigma Nutrition Radio has reached the 300th episode! To mark the occassion, Patreon supporters of the podcast and subscribers to the Sigma Synopsis email were able to submit questions about anything they wished.

In this episode, Gar Benn joins me to go through some of the questions submitted.

This episode focuses on all the random questions submitted about a range of things, from my schedule to religion to career highlights to living in Ireland, and everything in between!

Dr. Mark Hopkins is a lecturer in nutritional physiology at the University of Leeds, UK. His research focuses primarily on the physiological mechanisms of appetite control, and the interaction between diet, physical activity and appetite control. This includes examining the physiological and behavioural responses to dietary and exercise-induced weight loss.

Mark is a member of the Association for the Study of Obesity, the British Association of Sport & Exercise Science and The Nutrition Society.

Show notes: https://sigmanutrition.com/episode299/

David Zeevi is an independent research fellow at Rockefeller University in New York. His current work focuses on developing computational methods for studying microbial ecology in the human gut and in the marine environment, and its contribution to human and environmental health.

Previously he completed his PhD at the Weizmann Institute of Science in Israel under Prof. Eran Segal, studying the human microbiome and its effect on host health and personalized nutrition. He was lead author on two important studies to come from the lab, published in Nature and Cell respectively.

SHOW NOTES: https://sigmanutrition.com/episode298/

Cliff Harvey has a PhD in Nutrition from Auckland University of Technology (AUT), with his research focus being on ketosis, ketogenesis, and individual responses to diet. His research interests include MCTs, keto-induction, "keto-flu", and finding appropriate carbohydrate intake for individuals based on their metabolic state, activity and ethno-genetic factors.

He is a Registered Clinical Nutritionist in New Zealand, with over 20 years of experience as a practitioner. Cliff was one of the very first practitioners to begin prescribing and working with low-carb, high-fat (LCHF), ketogenic, and lower-carb, higher-protein diets in the late 1990s. Cliff is the founder of the Holistic Performance Institute.

SHOW NOTES: https://sigmanutrition.com/episode297

Alan Flanagan is currently a PhD researcher at the University of Surrey, UK. His research is in the general field of chrononutrition, with a specific focus on how calorie distribution and timing may impact health & energy balance. Alan has a Masters in Nutritional Medicine, also from the University of Surrey. Alan is also a qualified lawyer, practising in Dublin, Ireland before embarking on his PhD.

SHOW NOTES: https://sigmanutrition.com/episode296/

Ben House has a Ph.D. in Nutrition from the University of Texas at Austin. Ben has worked as a Strength and Conditioning Coach and Nutritionist since 2006. He is currently the owner and founder of Functional Medicine Costa Rica, where he hosts courses, mentorships and retreats. House has numerous publications in peer reviewed scientific journals such as The International Journal of Obesity, has presented his work at multiple international conferences, and lectures regularly on health and nutrition at The University of Texas.

SHOW NOTES: https://sigmanutrition.com/episode295/

Nicola Guess is a Registered Dietitian with a PhD in the dietary management of prediabetes from Imperial College London. She is currently Head of the Nutrition Unit at Dasman Diabetes Institute (DDI) in Kuwait. Nicola is a research fellow at King's College London where her research focuses on the role of diet in the prevention and management of type 2 diabetes.

She has a particular interest in the use of low-carbohydrate diets in the management of type 2 diabetes, and leads a research programme investigating dietary modification – including increasing protein or the use of very-low-calorie-diets – on the factors underlying type 2 diabetes.

Nicola received her Registered Dietitian qualification in the United States which included clinical rotations at the Baylor College of Medicine, and world-famous Weight Management Clinic at the Methodist Hospital in Houston, Texas.

Nicola's expertise in the area of diet and type 2 diabetes is well recognised. She is currently a National Institute of Clinical Excellence (NICE) Guidelines Expert Adviser and was a Diabetes UK Research Fellow. She sits on the Diabetes UK Clinical Guidelines Committee which sets priorities for diabetes research in the UK; is a panel member of the Royal College of General Practitioners Lifestyle Group and was previously a topic expert on the NICE Guidelines Committee for the Prevention of Type 2 Diabetes.

SHOW NOTES: https://sigmanutrition.com/episode294/

Jessica Setnick background in human behavior (she holds a Bachelor's degree in Anthropology from The University of Pennsylvania) combined with her expertise in dysfunctional and disordered eating (she is a Registered Dietitian with a Master's Degree and writes books and articles about eating disorders).

A Certified Eating Disorder Dietitian and CEDRD Supervisor, Jessica is the author of The Eating Disorder Clinical Pocket Guide and Eating Disorders Boot Camp. She is a co-founder of IFEDD, the International Federation of Eating Disorder Dietitians.

Prof. Alexandra Johnstone is recognized as a leading innovative UK researcher within the field of human appetite control and specifically, the role of dietary protein. She is a Professor at The Rowett Institute at the University of Aberdeen in Scotland.

She has published an extensive list of studies to assess the impact of diets on the body and the mind and to investigate how different meals and drinks affect our appetite, health and wellbeing.

SHOW NOTES: https://sigmanutrition.com/episode292/

Click here to subscribe to Sigma Nutrition Premium

Dr. Gabrielle Fundaro is a coach and science communicator for Renaissance Periodization coach. Dr. Fundaro is a former Assistant Professor of Exercise Science at Georgia Gwinnett College, and holds a PhD in Human Nutrition.

In This Episode We Discuss: - Bacertial diversity: eveness & richness - What is an "optimal" gut microbiome composition - How rapidly does it change on changing diet? - Relationship between microbiome and disease states: which way around does this occur?

SHOW NOTES: https://sigmanutrition.com/episode291/

Click here to subscribe to Sigma Nutrition Premium

Click here to subscribe to Sigma Nutrition Premium

In This Episode We Discuss:

How low is "too low" for low calorie days? How much do very low calorie days or fasting impact muscle retention? Is there a physiological benefit to diet breaks and refeeds?

Eric is currently a Research Fellow at Auckland University of Technology, New Zealand. His work is focused on training and nutrition interventions that could have implications for bodybuilders, powerlifters and other strength athletes. Eric has many peer reviewed publications and currently has many ongoing research projects and collaborations.

Previously, Eric completed his PhD at AUT. He also holds a BS in fitness and wellness, an MS in exercise science, and a MPhil in sports nutrition.

Once a former business consultant specialized in advanced statistical data analysis, Menno has MSc from the University of Warwick (UK) in that area. Menno's background in science and statistics helped him to develop a unique way of approach questions in fitness.

Menno is a published academic author and has spoken at some of the world's biggest evidence-based training conferences and events.

SHOW NOTES: https://sigmanutrition.com/episode290

Click here to subscribe to Sigma Nutrition Premium

Ciaran is a post-doc research fellow at the Exercise Medicine Research Institute (EMRI) at Edith Cowan University in Western Australia.

Ciaran completed his PhD in the Exercise and Behavioral Medicine Laboratory at The Ohio State University under the mentorship of Dr. Brian Focht. Here, his research focused on the physiological and psychosocial responses to physical activity lifestyle interventions in a variety of clinical populations including breast and prostate cancer, and individuals with knee osteoarthritis.

Ciaran is also strong advocate of the dissemination/translation of scientific research to a variety of audiences. He is the founder of REACH (Research in Exercise and Cancer Health), a company designed to provide evidence-based guidelines of physical activity to health/medical professionals and individuals with cancer.

SHOW NOTES: https://sigmanutrition.com

Ted is an online coach and podcaster. He has been in the fitness industry for over 20 years, with much of that spent as a sought-after personal trainer in Miami, Florida. During his coaching career he has worked with a variety of clients including Fortune 500 CEOs and celebrities, including Richard Branson and Robert Downey Jr. In more recent years he has continued to coach people online whilst being based in several different locations around the world.

Show notes: https://sigmanutrition.com/episode288/

Gregg Slater is head of education at Lift The Bar, a company providing education to fitness professionals. After completing his BSc in Sports and Exercise Science Gregg started out his professional life as a Physical Education Teacher before making the transition towards his passion for fitness as a Physical Training Instructor in the Royal Air Force for 10 years.

In 2015 he took up his role as Head of Education for Lift The Bar. Over this time Gregg has designed a number of acclaimed courses on a variety of topics, mentored trainers, consulted with gyms and runs regular educational seminars for personal trainers.

SHOW NOTES: https://sigmanutrition.com/episode287/

Click here to subscribe to Sigma Nutrition Premium

Dr. James Morton is a Professor of Exercise Metabolism at Liverpool John Moores University. He has an extensive list of published peer-review research in high impact journals, as well as being deeply involved in the highly-regarded sport science and nutrition programs at LJMU.

James was Head of Nutrition at Team Sky (now Team Ineos) during a period where the team captured 5 Tour de France titles. Previously, Dr. Morton worked as head performance nutritionist at Liverpool Football Club. He also also worked with professional and amateur boxers.

Show Notes: https://sigmanutrition.com/episode286/

Click here to subscribe to Sigma Nutrition Premium

Intro to Danny's framework for defining "health": 1) Physical Reality – 06.30; 2) Contentedness – 14.08; 3) Psychological Framework – 31.37

DUBLIN SEMINAR: https://sigmanutrition.com/healthseminar/

SHOW NOTES: https://sigmanutrition.com/episode285

Simone is an Intuitive Eating Counsellor, currently finishing MSc Nutrition and Behaviour at Bournemouth University. She is also a PhD Counselling psychology candidate. Her academic research area is body image and adaptive eating, and she practices as a therapist in the field of nutrition, chronic dieting, body image and eating disorders.

In This Episode We Discuss The scale of the problem of negative body image Tying appearance to self-worth & personal identity External drivers of negative body image Root causes of obesity Why "self-responsability" isn't helpful at scale Steps in modifying body image Self-talk: moving from negative to neutral to positive Can non-weight loss interventions improve health to the same degree as those that lead to weight loss in "at risk" groups (e.g. those with diabetes or with obesity)?

SHOW NOTES: https://sigmanutrition.com/episode284/

Dr. Williams is the Director of the Sports Genomics Laboratory and is a Reader in Sport and Exercise Genomics at Manchester Metropolitan University. Alun is also Honorary Senior Research Associate at University College London. He has a PhD from the University of Birmingham.

He has published expert position statements about the ethics and practicality of applying genetic technologies in sport. And was recently involved in the historic IAAF vs. Caster Semenya case related to testosterone levels within athletes with differences of sexual development (DSD).

SHOW NOTES: https://sigmanutrition.com/episode283/

Professor Louise Burke has been one of the most highly respected and accomplished sports nutrition researchers over several decades. She has been the head of sports nutrition at the Australian Institute of Sport (AIS) for nearly 30 years, publishing a vast number of important, novel and high-quality papers in the sports nutrition field.

Professor Bourke's research interests lie in nutritional intervention strategies for sporting performance. The goal of Louise's research is to find practical nutrition strategies that athletes and coaches can use to achieve optimum performance. Often this will involve examining metabolism during and after exercise to discover how complex systems work.

SHOW NOTES: https://sigmanutrition.com/episode282/

Click here to subscribe to Sigma Nutrition Premium

Dr. Jake Linardon is a Lecturer in Psychology at Deakin University, Melbourne Australia. He started working at Deakin in 2018, shortly finishing his PhD at Australian Catholic University (2017). He continues to research into eating disorders, with a primary focus on testing and evaluating a broad range of treatment approaches for eating disorders.

SHOW NOTES: https://sigmanutrition.com/episode281/

Click here to subscribe to Sigma Nutrition Premium

Dr Elliott-Sale is an associate professor in female physiology at Nottingham Trent University.

There, she is also the Head of the Musculoskeletal Physiology Research Group.

She is also responsible for teaching on the undergraduate and postgraduate Sport Science degree programmes.

Dr Elliott-Sale teaches mainly in the areas of Exercise Physiology and particularly in Female Physiology, Performance, and Health.

In This Episode We Discuss: --> Menstrual disorders: secondary amenorrhea (loss of 3 or more consectively) vs. oligomenorrhea (cycle longer than 45 days), vs.Functional --> Hypothalamic Amenorrhea (FHA) vs milder symptoms of some dysfunction --> What is happening on a hormonal level that ties in with menstrual issues? --> Understanding "energy availability" --> How do we quantify what is "low" energy availability? --> Relative Energy Deficiency in Sport VS. Female Athlete Triad --> Landmark papers that really advanced understanding of this concept Triad can lead to decreased estrogen. --> Implications for contraceptive pill users? --> Difference in risk between genders? --> Difference in expression of symptoms among genders? --> Reduced EA = increased illness/injury and thus more opportunities to train are lost. --> Recommendations for at risk athletes --> The screening and diagnosis of RED-S is challenging, as symptomatology can be subtle. --> Individuality: How great the energy deficiency needs to be for that individual to be symptomatic

SHOW NOTES: https://sigmanutrition.com/episode280

Links:

About This Episode:

Avrum Bluming received his MD from the Columbia College of Physicians and Surgeons. He spent four years as a senior investigator for the National Cancer Institute and for two of those years was director of the Lymphoma Treatment Center in Kampala, Uganda. He organized the first study of lumpectomy for the treatment of breast cancer in Southern California in 1978, and for more than two decades he has been studying the benefits and risks of hormone replacement therapy administered to women with a history of breast cancer.

Dr. Bluming has served as a clinical professor of medicine at USC and has been an invited speaker at the Royal College of Physicians in London and the Pasteur Institute in Paris. He was elected to mastership in the American College of Physicians, an honor accorded to only five hundred of the over one hundred thousand board-certified internists in this country.

Carol Tavris received her PhD in social psychology from the University of Michigan. Her books include Mistakes Were Made (But Not by Me), with Elliot Aronson; Anger: The Misunderstood Emotion, and The Mismeasure of Woman. She has written articles, op-eds, and book reviews on topics in psychological science for a wide array of publications — including the Los Angeles Times, the New York Times Book Review, the Wall Street Journal, and the TLS — and a column, "The Gadfly," for Skeptic magazine. She is a fellow of the Association for Psychological Science and has received numerous awards for her efforts to promote gender equality, science, and skepticism.

Links:

About This Episode:

Jackson Peos, PhD was the lead researcher on the ICECAP trial (Intermittent versus Continuous Energy restriction Compared in an Athlete Population), looks at the effect of including a "diet break" week after every 3 weeks of dieting, compared to a continuous hypocaloric diet for the duration of the full dieting period.

In This Episode We Discuss: - Theoretical reasons for including diet breaks and refeeds within dieting periods - Distinguishing between intermittent fasting protocols and intermittent moderate energy restriction (MOD-IER) - Lessons learned from the MATADOR trial - What might differ between obese and athletic populations - Design of Jackson's "ICECAP trial" - Determining the duration, frequency and magnitude of diet breaks, refeeds and energy restriction - Current best practices for implementing these strategies

Links:

About This Episode:

Eric is currently a Research Fellow at Auckland University of Technology, New Zealand. His work is focused on training and nutrition interventions that could have implications for bodybuilders, powerlifters and other strength athletes. Eric has many peer reviewed publications and currently has many ongoing research projects and collaborations.

In This Episode We Discuss:

Links:

About This Episode:

Nick Gant is Director of the Exercise Neurometabolism Laboratory at the University of Auckland.

His group uses interdisciplinary approaches from the nutritional sciences and neurosciences to investigate the role of nutrition in brain health and performance. Nick is particularly interested in foods and supplements that prevent brain fatigue and improve physical and cognitive function.

His research is currently funded by the Royal Society of New Zealand, the Health Research Council of New Zealand, and several industrial partnerships. He partners with clinicians and dieticians within the NZ Centre for Brain Research and provides scientific and educational support for elite athletes, government and military organisations

In This Episode We Discuss:

Links:

About This Episode:

Kate has both undergraduate and graduate degrees in Psychology and spent time as a psychology professor at a college and university level.

She currently is a health & nutrition coach, working for Precision Nutrition, where she has coached over 1,000 people. Now she coaches fitness professionals on how to be better coaches.

In This Episode We Discuss: --> Using an understanding of human psychology to improve coaching outcomes --> How we go about rationalizing our behaviour. --> How coaches can develop empathy --> Fitting the diet to your lifestyle: how much leeway/flexible does one give? --> The best skills a coach can teach themself --> Resilience --> Proactive and reactive coping strategies

Links:

About This Episode:

Bryan Chung is a plastic/hand surgeon and PhD research designer. He is a methodologist who improves people's relationship with science.

In This Episode We Discuss: --> Bryan's advice column for people who have "relationship problems with Science" --> If things merely confirm what you are already doing, why you should filter it out --> How to determine what is practically meaningful from a study --> The importance of establishing what the research question is --> How to deal with the daunting nature of statistics in research --> Why you're already good enough to start engaging with research

Links:

About This Episode:

Professor Barbora de Courten, MD PhD FRACP MPH is a Professor at Monash University, Australia. She is a National Heart Foundation Future Leader Fellow and a specialist physician with a PhD in epidemiology, extensive training in clinical trials (NIH) and a Master of Public Health (Monash University). She has expertise across the translational research continuum from epidemiology, human mechanistic studies to clinical trials and public health interventions through to practice.

She is passionate about research into holistic approaches to prevention and treatment of chronic diseases by promoting health through safe, low-cost and easily scalable interventions with the potential to have an immediate public health impact to prevent and treat chronic diseases. She believes this will impact not only health of individuals but also be beneficial to our society and environment we live in.

Her vision is to establish new strategies for prevention and management of chronic diseases, specifically obesity, diabetes and cardiovascular disease. Her goal is that her research findings will ultimately translate into treatment guidelines, reduced diabetes and cardiovascular morbidity and mortality and reduced healthcare costs.

In This Episode We Discuss: --> Mechanisms by which certain behaviours (inactivity, poor diet, smoking, etc.) increase chronic disease risk: inflammation, oxidative stress and advanced glycation (AGE formation). --> What is carnosine? --> How might carnosine supplementation reduce risk? --> Dosage and timing used in trials to date --> Prof. de Courten's trial showing improvements in insulin sensitivity and an oral glucose tolerance test --> As beta-alanine works by increasing muscle carnosine concentration, could it be useful for the health?

Links:

About This Episode:

Prof. Hawley is Director of the Mary MacKillop Institute for Health at Australian Catholic Universtiy in Melbourne, Australia.

He has published over 220 scientific manuscripts, written over 100 articles for technical journals and has authored numerous book chapters for exercise biochemistry and sports medicine texts.

He is an Associate Editor for Diabetologia and currently sits on the Editorial Boards of many international journals. He is a frequently invited speaker at both National and International scientific meetings.

John's primary research focus includes the interaction of exercise and diet on the regulation of fat and carbohydrate metabolism, particularly within skeletal muscle, the molecular basis of exercise training adaptation and the cellular bases underlying exercise-induced improvements in insulin action.

In This Episode We Discuss: --> Current work being done by Prof. Hawley's lab on circadian metabolomics Defining the human metabolome and circadian metabolomics --> Comparative analysis of the circadian metabolome in the serum versus peripheral tissues (i.e., skeletal muscle) --> Impact of high-fat or high-carb diet on the daily variation in metabolites --> How dietary intake is a strong zeitgeber for peripheral clocks --> Tissue-specificity of the human circadian metabolome --> Time-restricted feeding in animal models and in humans

Links:

About This Episode:

Alex is currently completing a PhD at the University of Brighton in the UK, investigating the implications of RNA sequencing in the detection of anabolic steroid use and the harnessing of the molecular mechanisms of "muscle memory". He is currently conducting research aiming to address a hypothesis that suggests that the myonuclei obtained via strength training and anabolic steroid usage are retained and therefore provide long term advantages to steroid users.

In This Episode We Discuss: --> The mechanism of hypertrophy via myonuclei accumulation --> Defining "muscle memory" in relation to myonuclei --> Animal models that show myonuclei don't dissappear after atrophy --> Anabolic steroids activate the stem cells in muscle (satellite cells) resulting in a donation of their nuclei into muscle fibres --> How drug testing works --> How you prove someone has taken exogenous testosterone via T:E ratios --> The Athlete Biological Passport --> Thoughts on the recent Jon Jones case --> Next generation "omic" technologies such as transcriptomics could enhance the testing protocols

Links:

About This Episode:

Lyndon is Head of Education at JPS Health & Fitness in Melbourne, Australia.He has a Bachelor of Applied Science in Exercise and Sport Science and is completing a Masters in High Performance Sport Science. He is also a qualified strength and conditioning coach and has coached many athletes over the past number of years.

Jacob is the founder and director of JPS Health & Fitness in Melbourne, Australia. Having worked in the industry for close to a decade, Jacob's wealth of knowledge coupled with his experience in the trenches has led him to become one of Melbourne's most sought out trainers. His role has extended fate beyond working with his beloved clients, to now mentoring aspiring personal trainers, holding workshops and seminars, and writing for the nations personal training governing body, Physical Activity Australia.