Sigma Nutrition Radio

Danny Lennon

  • 1 hour 6 minutes
    #556: Can We Restore the Gut Microbiome Through Dietary Changes? – Anissa Armet, PhD

    There is research suggesting that industrialization has significantly altered the composition of our gut microbiota, with certain microbial species now absent in many industrialized populations.

    Given the known associations between gut microbiome diversity and health, researchers have begun investigating whether restoring lost microbial species and adopting dietary patterns similar to those of non-industrialized populations could lead to measurable health benefits.

    In a newly-published study, the investigators aimed to explore whether L. reuteri could be successfully reintroduced into the microbiome through the “Restore Diet” and whether such a shift would result in improvements in key cardiometabolic and inflammatory markers.

    One of the authors, Dr. Anissa Armet, is on the podcast to discuss this area and both the potential and limitations of microbiome restoration efforts.

    Timestamps
    • [03:48] Interview start
    • [08:45] Understanding gut microbiome restoration
    • [11:44] Challenges in microbiome research
    • [21:03] Study design and objectives
    • [43:23] Key findings and results
    • [47:46] Future research directions
    • [01:04:04] Key ideas segment (premium-only)
    Links
    11 March 2025, 5:00 am
  • 59 minutes 29 seconds
    #555: What Should the Dietary Guidelines Say? – Prof. Christopher Gardner

    Every five years, the U.S. Dietary Guidelines are updated based on the latest scientific evidence to help shape national nutrition recommendations. A panel of experts was assembled to review the existing research, evaluate new findings, and provide recommendations that will inform the next edition of the guidelines.

    One of the committee members involved in this process is Professor Christopher Gardner, a leading nutrition scientist at Stanford University, who joins us to share key insights from the committee’s work.

    In this discussion, Professor Gardner provides an inside look into how the committee evaluated dietary patterns, the role of plant-based proteins, and the ongoing debate surrounding ultra-processed foods. He explains the rigorous process of reviewing scientific literature, the challenges in translating research into policy, and the critical role of health equity in shaping the recommendations.

    By exploring these themes, this episode aims to provide clarity on the scientific foundation behind the upcoming dietary guidelines. Whether you’re a nutrition professional, researcher, or someone interested in how dietary recommendations are formed, this conversation sheds light on the key discussions shaping the future of nutrition policy.

    Timestamps
    • [03:38] Interview begins
    • [07:18] The rigorous process behind formulating dietary guidelines
    • [12:10] Key questions addressed and major findings from the report
    • [25:41] Identifying nutrients of concern and refining dietary patterns
    • [33:39] The importance of health equity in dietary recommendations
    • [36:04] Reassessing dairy’s role in different population groups
    • [41:05] Shifting the focus towards plant-based protein sources
    • [47:52] The debate on ultra-processed foods and public health implications
    • [58:24] Key Ideas segment (Premium-only)
    Related Resources
    4 March 2025, 5:00 am
  • 1 hour 13 minutes
    #554: Crucial Ideas for Understanding Nutrition Science

    Understanding the complexities of diet-disease relationships requires a nuanced approach to nutritional science. Unlike other scientific disciplines, nutrition research often grapples with the inherent challenges of studying dietary patterns and nutrient intakes in free-living populations over long periods.

    The cumulative effects of dietary exposures, combined with the necessity to control for confounding factors such as total energy intake and population-specific dietary habits, highlight the need for rigorous study designs and careful interpretation of findings.

    Despite their utility, these methods are often misunderstood or misrepresented in public discourse. Addressing these misunderstandings requires a clear communication of key principles underpinning nutritional science, including the role of cumulative exposure, the importance of contextualizing absolute and relative risks, and the necessity of evaluating the long-term effects of dietary patterns.

    This episode aims to provide a comprehensive overview of these essential ideas, equipping readers with the tools to critically appraise the evidence and engage meaningfully with the ongoing conversation around nutrition research.

    Timestamps
    • [03:26] Understanding nutrition science: core concepts
    • [06:01] Standards of proof in nutrition research
    • [19:39] Unique challenges in nutrition research
    • [26:30] High vs. low exposure in nutrition studies
    • [34:34] Challenges in nutrition randomized control trials
    • [39:29] Understanding null by design in nutrition trials
    • [41:58] The importance of temporal relationships in diet and disease
    • [43:55] Relative risk vs. absolute risk
    • [57:16] The role of substitution and adjustment in nutrition studies
    Related Resources
    25 February 2025, 5:00 am
  • 40 minutes 58 seconds
    #553: Healthy Habits for Fertility and Reproductive Health – Marjorie Nolan Cohn, RD

    This episode focuses on the intersection of nutrition, lifestyle, and women’s health, with a particular emphasis on managing complex conditions such as PCOS, endometriosis, and premenstrual dysphoric disorder (PMDD).

    Registered dietitian Marjorie Nolan Cohn shares insights from over two decades of clinical practice, highlighting the importance of addressing foundational health behaviors—such as adequate sleep, hydration, and nutrient-dense dietary patterns—before introducing targeted interventions like supplementation.

    Marjorie explores the nuanced relationship between body weight, metabolic health, and fertility, while addressing misconceptions around weight loss as a primary health goal. The episode examines the role of long-term, individualized care in improving symptoms and outcomes for women experiencing significant menstrual-related challenges.

    Practical considerations for practitioners, including strategies to build trust, identify key barriers, and provide holistic support, are outlined alongside the importance of interdisciplinary collaboration to improve care quality.

    Marjorie Nolan Cohn is a registered dietitian with a Masters Degree in Food and Nutrition Science from the Indiana University of Pennsylvania. She is the Clinical Director of Berry Street, a company providing virtual in-network nutritional counseling to people across the US.

    Timestamps
    • [04:32] Beginning of the interview
    • [08:39] The role of nutrition in fertility
    • [13:40] Understanding PCOS and endometriosis
    • [16:28] Barriers to accurate women’s health diagnoses
    • [19:03] Exploring diet and lifestyle strategies
    • [23:28] Addressing challenges in women’s health and nutrition
    • [39:01] Closing remarks and final takeaways
    Related Resources
    18 February 2025, 5:00 am
  • 41 minutes 4 seconds
    #552: Diet & Sleep Interactions – Marie-Pierre St. Onge, PhD

    Over the past couple of decades, renowned researcher Dr. Marie-Pierre St-Onge has uncovered fascinating links between how we sleep and what we eat, revealing how these two lifestyle factors influence energy balance, cardiovascular health, and metabolic function.

    In this episode we’ll explore Dr. St-Onge’s findings on sleep regularity and its association with reduced mortality risk, providing actionable insights for optimizing your lifestyle. With a focus on combining rigorous methodologies and controlled dietary interventions, her research sheds light on the complex mechanisms connecting sleep, diet, and metabolic health.

    Timestamps:

    • [03:39] Dr. St-onge's academic journey and evolution of her research interests
    • [07:03] Overcoming methodological challenges in sleep and nutrition research
    • [10:20] The importance of sleep regularity for health
    • [15:44] Exploring the bidirectional connection between diet and sleep
    • [23:40] Unpacking the mechanisms linking diet to sleep quality
    • [37:33] Practical recommendations for optimizing sleep and diet

    Links:

    11 February 2025, 5:00 am
  • 17 minutes 39 seconds
    Multivitamin Nihilism: Is it Actually Worthless to Supplement? (SNP37)

    Multivitamin and multimineral supplements have long been a topic of both scientific inquiry and public debate. While they are often marketed as convenient solutions for achieving nutritional adequacy, their true value remains contentious.

    Are these supplements essential insurance policies against nutrient deficiencies, or are they merely expensive placebos?

    Importantly, how should we weigh their potential benefits against the lack of robust evidence for long-term health outcomes such as reduced mortality or chronic disease risk? These questions demand a nuanced exploration, grounded in the context of specific populations and individual needs.

    Ultimately, the role of multivitamin supplements cannot be assessed in isolation but must be viewed through the lens of context and specificity. How do we balance the biological plausibility of benefits against the variability of individual diets, the presence of fortification policies, and the challenges of achieving dietary adequacy in certain life stages?

    These considerations invite a more thoughtful and less binary discussion about whether, when, and for whom multivitamins are a worthwhile addition to the diet.

    Timestamps
    • [00:22] The debate on multivitamins: worthless or beneficial?
    • [00:53] Rationale behind multivitamin use
    • [04:04] Modern nutritional adequacy and multivitamins
    • [07:10] Evidence supporting multivitamin use
    • [23:39] Long-term health outcomes and multivitamins
    • [41:43] Cognitive outcomes
    • [50:18] Pregnancy and multivitamin use
    Related Resources
    4 February 2025, 5:00 am
  • 1 hour 2 minutes
    #551: How to Shift from Short-term Dieting to Sustainable Lifestyle Changes – Laurin Conlin

    While the fitness industry often emphasizes short-term goals such as rapid weight loss or aesthetic improvements, a growing body of evidence highlights the importance of fostering long-term habits for health and wellbeing. Understanding how psychological frameworks intersect with physical health behaviors is key to empowering clients and overcoming the challenges posed by rigid dieting practices or the influence of social media culture.

    Bodybuilding and fitness culture serve as both a microcosm and an extreme example of the challenges faced in this space. As the boundaries between physique sports and general fitness blur, many enthusiasts adopt unsustainable habits without fully understanding their long-term implications. How can fitness professionals effectively guide clients toward intrinsic motivations and healthier relationships with food and exercise while balancing the reality of external pressures?

    In this episode, Laurin Conlin offers her insights based on her coaching experiences, as well as formal training in exercise sciences and mental health counselling. Dr. Eric Trexler co-hosts the episode with Danny Lennon.

    Timestamps
    • [05:41] Challenges in dieting and coaching practices
    • [09:58] Bridging physical and mental health through coaching practices
    • [13:15] Recognizing and navigating disordered eating behaviors in fitness clients.
    • [22:01] The physiological and psychological challenges in physique sports.
    • [34:52] Fitness culture and social media influence
    • [37:19] Misunderstanding intuitive eating
    • [41:23] Using motivational interviewing and reflective listening to guide clients
    • [52:13] Integrating mental health practices in fitness and nutrition coaching
    • [62:13] Key Ideas segment (Premium-only)
    Related Resources
    28 January 2025, 5:00 am
  • 53 minutes 10 seconds
    #550: Eating Disorder Risk in Sport, Wellness & Fitness – Jillian Lampert, PhD, RD

    Eating disorders and disordered eating behaviors represent complex, multifaceted challenges that affect individuals across all demographics, yet they remain widely misunderstood and under-recognized. These issues often extend beyond the stereotypical images associated with eating disorders, touching everything from rigid “clean eating” obsessions to the normalized extremes of diet culture.

    At the heart of these behaviors lies a disruption in one’s relationship with food, often fueled by societal pressures, unrealistic body ideals, and a pervasive focus on aesthetics over health. While these challenges are tenacious, recovery and improved relationships with food are possible with the right interventions, resources, and awareness.

    In this episode, Danny talks to Dr. Jillian Lampert, a registered dietitian with a PhD in public health nutrition, with a speciality in eating disorders and disordered eating.

    Timestamps
    • [02:56] – What are eating disorders? a breakdown of core concepts
    • [05:15] – Beyond stereotypes: the widespread impact of eating disorders
    • [14:41] – Disordered eating in sports and fitness: risks and realities
    • [19:41] – Guidance for practitioners: recognizing and addressing red flags
    • [22:50] – Barriers in treating eating disorders: challenges and solutions
    • [43:50] – Advocacy and systemic change: the future of eating disorder care
    Related Resources
    21 January 2025, 5:00 am
  • 1 hour 19 minutes
    #549: Are We Doomed? Trust, Misinformation, and the Future of Health & Fitness Science – Joe Klemczewski, PhD

    In a world flooded with information, discerning fact from fiction in fitness and nutrition has never been more challenging—or more important. The rise of social media and democratized science has given everyone a platform, but not all voices are equal.

    How do we navigate a landscape where influencers with massive followings wield the same credibility as seasoned experts? Why do pseudoscientific trends gain traction while nuanced evidence gets lost in the noise?

    In this episode we also dive into the evolution of coaching, examining how the obsession with quantifiable metrics has shifted the focus away from human connection. How can professionals balance the drive for scalable success with the need for meaningful client relationships? And what lessons can we draw from decades of shifts in the fitness industry to stay resilient amid rapid societal and technological changes?

    Timestamps
    • [04:33] Eric’s personal journey and influence
    • [06:08] Evolution of bodybuilding coaching
    • [10:32] Challenges in interpreting scientific research
    • [17:35] Historical trends in diet and nutrition
    • [25:49] Information overload and misinformation
    • [43:07] Understanding fractional counting in hypertrophy
    • [44:24] Challenges in communicating scientific concepts
    • [47:27] The psychology of persuasion
    • [49:07] The role of marketing in science communication
    • [54:46] Balancing data and intuition in coaching
    • [01:03:59] Navigating the future of nutrition coaching
    • [01:08:34] Building trust and connection with clients
    Related Resources
    15 January 2025, 5:00 am
  • 21 minutes 56 seconds
    IGF-1 and Diet: Cause For Concern? (SNP36)

    IGF-1 (Insulin-Like Growth Factor 1) has emerged as a hot topic in health and nutrition discussions, often linked to longevity, cancer risk, and metabolic health.

    On one hand, IGF-1 is essential for growth, repair, and metabolic regulation; on the other, it is sometimes associated with disease processes, including cancer and cognitive decline.

    For those intrigued by the intersection of nutrition, biomarkers, and disease prevention, IGF-1 offers an opportunity to explore how science grapples with these complexities.

    Claims about manipulating IGF-1 through dietary changes — whether by reducing protein or adopting fasting protocols — are common. But does the evidence support these claims?

    If you’re curious about IGF-1 and the relationships between diet, disease, and healthy aging, in this Premium-exclusive episode Danny and Alan discuss this fascinating topic.

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

    Timestamps
    • [02:21] IGF-1 and Diet: Examining the Relationship
    • [09:15] IGF-1 as a Biomarker: Challenges with Sensitivity and Specificity
    • [11:54] IGF-1 and Cancer Risk: Insights and Complexities
    • [25:51] IGF-1 in Aging: Cognitive Function and Longevity Considerations
    • [43:38] Key Takeaways: IGF-1, Diet, and Practical Advice
    Related Resources
    8 January 2025, 5:00 am
  • 48 minutes 7 seconds
    #548: Disordered Eating and Body Image in the Fitness Industry – Michelle Carroll

    Fitness pursuits can bring various benefits. However, within the modern fitness industry there is a complex interplay of body image ideals, societal pressures, and disordered eating behaviors.

    Research continues to illuminate how certain practices and messaging within the industry—such as the overvaluation of leanness or the impact of social media personas—can fuel body dissatisfaction and disordered eating.

    For fitness coaches and enthusiasts alike, this raises important questions:

    • What defines success in fitness?
    • How can individuals engage in training and nutrition without falling into harmful traps?
    • And how can professionals align their practices with values that support long-term well-being for themselves and their clients?

    In this episode, Michelle Carroll, a PhD researcher in clinical psychology, explores these questions in depth. Drawing on her academic work and personal experiences, she discusses the implications of fitness industry norms, the challenges of online coaching, and practical steps for fostering healthier relationships with food and body image.

    Timestamps
    • [01:15] Defining disordered eating and body image
    • [03:47] Motivations behind this research
    • [05:37] Impact of the fitness industry on body image
    • [08:29] Challenges and misconceptions about body image
    • [14:26] Physical capital and pressures on fitness professionals
    • [18:20] Consequences of harmful fitness industry messaging
    • [35:04] Positive changes and gaps for future research
    • [40:16] Practical advice for professionals and individuals
    Related Resources
    1 January 2025, 5:00 am
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