Sigma Nutrition Radio

Danny Lennon
  • 4.8 (381)
  • Nutrition
  • Updated Weekly

Discussions about the science of nutrition, dietetics and health. The podcast that educates through nuanced conversations, exploring evidence and cultivating critical thinking. Hosted by Danny Lennon.

  1. 6d ago

    #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: Go to episode page Join the Sigma newsletter for free Subscribe to Sigma Nutrition Premium Enroll in the next cohort of our Applied Nutrition Literacy course Dr. Tiller's website Tiller & Phillips, 2023 – How Skepticism (not Cynicism) Can Raise Scientific Standards and Reform the Health and Wellness Industry Tiller et al., 2024 – The Nontechnical Summary: A New Initiative to Enhance the Translation of Sports Science Research and Reduce the Spread of Misinformation

  2. Aug 25

    #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: Go to episode page Join the Sigma newsletter for free Subscribe to Sigma Nutrition Premium Enroll in the next cohort of our Applied Nutrition Literacy course Instagram: @gemmcguinnness Verus Performance Davey Nutrition Gemma's Substack

  3. Aug 18 ·  Bonus

    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: 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.

  4. Aug 11

    #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: Go to episode page (with resources) Join the Sigma newsletter for free Subscribe to Sigma Nutrition Premium Enroll in the next cohort of our Applied Nutrition Literacy course Instagram: @austin_barbellmedicine Twitter: @AustinBaraki

  5. Aug 4

    #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: Go to episode page Join the Sigma newsletter for free Subscribe to Sigma Nutrition Premium Enroll in the next cohort of our Applied Nutrition Literacy course Paper: Plant-Based Diets, Ultra-Processed Foods, and Risks of Mortality and Major Chronic Diseases: A Prospective Cohort Study

  6. Jul 21

    #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: Go to episode page Join the Sigma newsletter for free Subscribe to Sigma Nutrition Premium Enroll in the next cohort of our Applied Nutrition Literacy course Past episode #326: Adaptability & Autonomy in the Nutrition Coaching Process Krista's website: kristascottdixon.com Instagram: @stumptuous 1% Better Academy The textbook: Applied Nutrition Coaching and Counseling: ebook version US Canada UK International

  7. Jul 14

    #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

  8. Jul 7

    #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: Go to episode page (incl. links to studies) Join the Sigma newsletter for free Subscribe to Sigma Nutrition Premium Enroll in the next cohort of our Applied Nutrition Literacy course

See All (642)

Hosts & Guests

4.8
out of 5
381 Ratings

About

Discussions about the science of nutrition, dietetics and health. The podcast that educates through nuanced conversations, exploring evidence and cultivating critical thinking. Hosted by Danny Lennon.

Information

  • Creator
    Danny Lennon
  • Years Active
    2014 - 2026
  • Episodes
    642
  • Rating
    Explicit
  • Copyright
    © Sigma Nutrition
  • Show Website
    Sigma Nutrition Radio

You Might Also Like