• 42 minutes 39 seconds
    #621: Hedonic Overeating, Food Wanting and Impact of Perception – Prof. Graham Finlayson

    Why do some foods feel difficult to stop eating, while others can be highly enjoyable without prompting the same tendency to overconsume? Answering this requires a clearer understanding of food reward, including the distinction between liking a food, wanting it, and perceiving it as easy to overeat.

    In this episode, we examine how nutritional composition, sensory characteristics, learned beliefs and the eating context may shape hedonic overeating. It also considers the limits of using broad food categories to explain complex eating behaviour.

    Discussing all this is Professor Graham Finlayson, professor of Psychobiology at the University of Leeds, whose research focuses on human appetite, food reward and the psychological processes involved in eating behaviour and weight control.

    Timestamps
    • [04:02] Prof. Finlayson's research
    • [06:06] Food reward
    • [07:13] Liking versus wanting
    • [12:43] Measuring wanting in research
    • [15:27] Does wanting predict overeating?
    • [16:36] Study on hedonic overeating
    • [23:19] Perception and context effects
    • [26:24] Does ultra processing classification add anything?
    • [36:09] Key takeaways and future work
    • [40:35] Premium key ideas
    Links/Resources:
    22 September 2026, 6:00 am
  • 57 minutes 32 seconds
    #620: BPC-157 and Peptide Medications: What Do We Know? – Jordan Feigenbaum, MD

    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.

    Timestamps

    • [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

    • [56:20] Key Ideas segment (Premium members only)
    Episode Resources
    15 September 2026, 6:00 am
  • 1 hour 3 minutes
    #619: How Much Fish Should a Healthy Diet Contain?

    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.

    Timestamps

    • [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)

    Episode Resources
    8 September 2026, 6:00 am
  • 56 minutes 55 seconds
    #618: How Wellness & Optimisation Culture Can Commodify Science – Nick Tiller, PhD

    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.

    Timestamps:

    • [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)

    Episode Resources:
    1 September 2026, 6:00 am
  • 46 minutes 40 seconds
    #617: What Does Effective Athlete Support Look Like in Practice? – Gemma McGuinness

    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.

    Timestamps:
    • [02:38] Interview start

    • [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:

    25 August 2026, 6:00 am
  • 21 minutes
    Fiber: Independent Benefits or Just a Proxy for Healthy Foods?

    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:

    1. Fiber: Independent effect or proxy for healthy foods?
    2. Exposure frequency for matched dose of red meat
    3. MTHFR gene mutations and 5-MTHF
    4. Typical fish oil supplements vs pharmaceutical-grade products
    5. Health impacts of saturated fat in coconut products
    6. Do I need to consume whole grains?
    7. 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.

    18 August 2026, 6:00 am
  • 1 hour 15 minutes
    #616: More Testing, Better Health? Harms of Overdiagnosis & Overtreatment - Austin Baraki, MD

    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.

    Timestamps:
    • [03:35] What screening means
    • [06:36] Choosing what to screen
    • [11:59] Sensitivity and specificity
    • [16:54] Predictive value and prevalence
    • [22:16] Harms of screening and testing
    • [31:02] Overdiagnosis and biases
    • [41:40] The $50,000 physical
    • [44:49] Overdiagnosis vs false positives
    • [53:03] Overtreatment and surveillance
    • [57:22] Clinician action bias
    • [01:02:30] What to screen for

    Links:

    11 August 2026, 6:00 am
  • 56 minutes 18 seconds
    #615: Why Processing Doesn't Determine the Healthfulness of Plant-Based Diets – Alysha Thompson, PhD

    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.

    Timestamps
    • [03:02] Interview start
    • [05:08] The key research question
    • [07:52] Study design
    • [17:25] Building diet scores
    • [21:11] NOVA classification challenges
    • [25:04] Key findings
    • [38:30] NOVA debate and stance
    • [43:44] Adjustments and mediators
    • [48:11] Future research directions
    • [54:37] Key ideas (premium-only)
    Resources:
    4 August 2026, 6:00 am
  • 56 minutes 30 seconds
    #614: The Human Skills of Nutrition Coaching – Krista Scott-Dixon, PhD

    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.

    Timestamps
    • [06:10] What makes a competent practitioners?
    • [11:17] Scope of practice line
    • [17:49] Therapeutic alliance
    • [23:33] Applying compassion and acceptance
    • [31:18] LLMs vs human connection
    • [34:40] Meta skills for practitioners
    • [38:51] Getting better feedback
    • [44:23] Collaboration and autonomy
    • [55:44] Key ideas recap

    Links:

    21 July 2026, 6:00 am
  • 57 minutes 18 seconds
    #613: Supplement Safety & Medication Interactions – Giulia Guerrini, MPharm

    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.

    Timestamps:
    • [02:39] Interview start
    • [05:21] Why context matters
    • [06:38] Timing and formulation
    • [12:58] Rating interaction risk
    • [22:39] Berberine benefits and interactions
    • [27:33] Adaptogens quality concerns
    • [30:15] Melatonin safety questions
    • [36:30] Stacking supplements risks
    • [41:50] Quality control and regulation
    • [55:35] Key ideas segment (premium-only)

    Links:

    • Free trial of Examine Clinician Edition – For health & nutrition professionals. Includes the Supplement Navigator (safety and interaction checking), plus all other Examine tools (study summaries, supplement database, in-depth guides, etc.)
    • Free trial of Examine+ – For anyone wanting to make evidence-based decisions about supplements and health. Includes: 100+ study summaries a month. The full supplement database. In-depth guides. ExamineAI. Doesn't include the Supplement Navigator.
    • Go to episode page
    • Subscribe to Sigma Nutrition Premium
    14 July 2026, 6:00 am
  • 38 minutes 59 seconds
    #612: Does Sweet Taste Exposure Actually Develop Preference? – Prof. Katherine Appleton

    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:

    • [04:23] Interview starts
    • [07:35] Sweetness terms explained
    • [10:17] Sweet liker phenotypes
    • [14:03] Liking vs wanting vs preference
    • [19:18] Trial evidence overview
    • [23:48] Policy and practical impact
    • [30:41] Why we eat foods

    Links:

    7 July 2026, 6:00 am
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