Sigma Nutrition Radio

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#548: Disordered Eating and Body Image in the Fitness Industry – Michelle Carroll Jan 01, 2025

Show notes

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

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Michelle's website
Michelle on Instagram: @michellecarroll1
Disordered Eating Informed – Course

#547: Healthspan, Healthy Ageing & Chronic Disease – Best of 2024 Dec 23, 2024

Show notes

Healthspan, healthy ageing, and chronic disease are pivotal topics in today's health discourse, emphasizing not just the length of life but the quality of those additional years. Focusing on healthspan means striving for a longer period of life free from disease and disability, which is increasingly important as global life expectancies rise. Healthy ageing involves adopting lifestyle habits that promote physical, mental, and social well-being throughout the lifespan, thereby reducing the risk of chronic diseases such as heart disease, diabetes, and neurodegenerative disorders.

Addressing chronic diseases risk requires a proactive approach centered on prevention and early intervention. By prioritizing healthspan and healthy ageing, individuals can significantly decrease the likelihood of developing chronic illnesses, leading to improved quality of life and reduced healthcare costs.

Sigma Nutrition Radio has consistently addressed these critical themes across many episodes. In this episode, we go back over some of the best episodes of 2024 in this area, including discussions on Alzheimer's, cholesterol-lowering medications, impact of exercise, and the debate about red meat.

Timestamps

(03.12) Alzheimer's: Genetic susceptibility vs. modifiable factors
(14.59) Heart disease: the "risk factor, disease, event" framework
(22.10) The strength of evidence we have for the impact of exercise on mortality and longevity
(28.23) Why high blood pressure is so problematic
(37.23) Where do we see risk for unprocessed red meat?
(48.34) The evolution over the years of dietary fat research
(53.20) Claims about the proposed risks of consuming seed oils
(56.16) How does fat quality impact heart disease risk?
(60.35) History of Portfolio Diet research for reducing LDL-C

Episodes referenced:

512: Alzheimer's Disease – Drs. Ayesha & Dean Sherzai
525: Cholesterol-Lowering Medication – Dr. Paddy Barrett
524: Strength & Fitness Levels for Reducing Chronic Disease Risk & Promoting Health Ageing – Jordan Feigenbaum, MD
527: How to Prevent & Treat Hypertension – Dr. Mohammed Alo, DO
528: Is Unprocessed Red Meat Problematic for Our Health?
532: Dietary Fat: Evidence vs. Misinformation – Alice Lichtenstein, DSc
515: Does Dietary Fat Quality Causally Affect Atherosclerosis Risk? – Jacob Christensen, PhD
507: Does a Higher Portfolio Diet Score Reduce Heart Disease? – Andrea Glenn, PhD

Links:

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#546: Professional Standards & Scope of Practice for Nutrition Professionals – Alex Thomas Dec 18, 2024

Show notes

Navigating the complex and often underemphasized requirements of professional standards, legal considerations, and insurance can be challenging for sports nutrition practitioners and personal trainers.

Many professionals, especially early in their careers, may overlook or minimize these responsibilities, focusing primarily on the practical and enjoyable aspects of helping clients achieve their goals. However, staying informed and adhering to these standards is not only essential for providing ethical, competent service but is also crucial for minimizing liability.

Ignoring or misinterpreting scope-of-practice guidelines and insurance limitations can leave well-meaning professionals exposed to significant legal and financial risks that could have lasting consequences on their careers.

In this episode, Alex Thomas joins Danny Lennon and Eric Helms to discuss the essential, if often overlooked, responsibilities that define a successful and resilient career in sports nutrition.

Together, they explore best practices for insurance, scope of practice, and the importance of aligning with professional organizations that provide educational and legal support.

Timestamps

[01:57] The SNA Introduction
[03:31] The importance of professional standards
[09:58] Legal consequences and real-world examples
[15:23] Insurance and scope of practice
[23:27] Navigating the gray areas in nutrition practice
[30:51] Legal risks in nutrition advice
[34:50] Ethical dilemmas and referral networks
[36:53] Emerging trends and risks in nutrition services
[48:49] Becoming a competent sports nutrition professional

Links

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Sports Nutrition Association

#545: Carbohydrate Metabolism, Performance & Metabolic Health – Prof. Javier Gonzalez Dec 10, 2024

Show notes

Carbohydrate metabolism and metabolic health have become central themes in the science of nutrition, with questions about fuel utilization, the impact of different diets, and the potential of ketone supplements driving new research.

As researchers continue to uncover how the body adapts to various energy sources, there are emerging insights into how glucose tolerance, glycogen utilization, and even ketogenic diets influence not only physical performance but also long-term health outcomes.

Understanding how the body responds to different energy sources, particularly in relation to carbohydrate restriction, brings crucial context to popular nutrition strategies and the potential benefits—or trade-offs—they offer.

In this episode, Professor Javier Gonzalez joins to discuss these topics in detail, exploring the latest findings on how dietary choices affect athletic performance, chronic disease risk, and the mechanisms underlying metabolic adaptations.

You will gain insight into topics like reactive hypoglycemia, carbohydrate oxidation, and why individualized responses to diet matter.

Timestamps

[01:36] Understanding carbohydrate metabolism
[06:33] The role of glucose in metabolic health
[09:59] Exercise and glucose dynamics
[17:35] Carbohydrate intake and athletic performance
[25:03] Diet impact on exercise and metabolism
[30:44] Pre-workout carbohydrates and reactive hypoglycemia
[35:31] Recent study: Ketogenic diet vs. sugar restriction
[41:09] Future research directions in metabolic health
[45:07] Ketone esters and their role in exercise performance
[49:22] Carbohydrate metabolism and common misconceptions

Links

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Paper: Ketogenic diet but not free-sugar restriction alters glucose tolerance, lipid metabolism, peripheral tissue phenotype, and gut microbiome: RCT

Appetite and Satiety: Key Concepts and Practical Insights (SNP35) Dec 03, 2024

Show notes

Appetite and satiety are fundamental concepts shaping how we eat, why we feel hunger, and what keeps us satisfied after meals. From the biological signals sent by our gut to the psychological influences of food cues, understanding these processes can provide valuable insights into how we manage our food intake.

In this episode, we delve into the interplay between hormones, food properties, and external factors that regulate appetite and fullness, exploring how these mechanisms work together—or sometimes fail—in modern eating environments.

We will examine fascinating topics such as the satiety cascade, sensory-specific satiety, and the impact of nutrient composition on hunger regulation. This episode also highlights how individual differences, such as satiety phenotypes, shape eating behavior, offering a nuanced perspective on the science of satiety.

Whether you're interested in applying these concepts to your diet or supporting others in managing hunger, this discussion offers practical takeaways grounded in scientific evidence.

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

Timestamps

[02:22] Understanding appetite and satiety
[07:28] Biological mechanisms behind hunger regulation
[10:57] Sensory and psychological cues affecting food intake
[26:54] Nutrient composition and its influence on satiety
[43:11] Practical strategies for managing hunger

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#544: Genetic Variants and Response to Nutrients – Martin Kohlmeier, MD PhD Nov 26, 2024

Show notes

In the realm of nutrition science, individual differences are more profound and impactful than many realize. For decades, we've developed dietary recommendations with a "one-size-fits-all" approach, assuming that most people respond similarly to specific nutrients. But Dr. Martin Kohlmeier, a pioneer in precision nutrition, challenges this very notion.

How might an individual's genetic makeup alter their need for certain nutrients?

With advances in nutrigenetics, we're beginning to see how personalized nutrition could bridge long-standing gaps in dietary efficacy. Dr. Kohlmeier's work highlights fascinating examples, from the APOE4 gene's influence on cholesterol metabolism to variations in folate metabolism that could affect everything from heart health to birth outcomes.

As Dr. Kohlmeier explains, precision nutrition is not simply about adding genetic testing to a wellness regimen. Instead, it requires rethinking nutrition research from the ground up—ensuring studies capture these individual variations and that public health policy moves beyond broad averages.

With genetic testing now more accessible than ever, could commercial pressures and oversimplified testing derail the science before it even gets going? In this episode, we dive deep into the potential and pitfalls of precision nutrition, exploring the future of personalized dietary advice and the road to truly individualized health.

Timestamps

[02:33] Introduction of Dr. Martin Kohlmeier and his background
[05:10] Rethinking assumptions in nutrition science
[07:42] The role of genetic variations in nutrient responses
[13:15] Practical examples of genetic impact on nutrition
[22:55] Misinformation and commercial misuse in nutrigenetics
[29:48] Case studies: cholesterol sensitivity (APOE4) and folate metabolism (MTHFR)
[41:03] Public health implications and the need for tailored research
[49:27] Future directions and the path forward for precision nutrition

Links

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Kohlmeier, 2023 – One size does not fit all: on the need for categorical stratification in nutrition science, practice and policy

#543: Eye Health & Nutrition – Prof. John Nolan Nov 19, 2024

Show notes

In this episode, we dive deep into the world of ocular nutrition with Professor John Nolan, exploring how specific nutrients can play crucial roles in preserving eye health, improving vision and supporting cognitive function.

With age-related macular degeneration (AMD) affecting millions globally, Professor Nolan sheds light on groundbreaking research showing how certain carotenoids—natural pigments found in plant foods—could impact eye health and perhaps even neurodegenerative conditions like Alzheimer's disease.

But what are these compounds exactly, and why are they so impactful?

Through in-depth clinical studies, Nolan has identified optimal nutrient formulations that could bridge the gap in conditions as diverse as macular degeneration and cognitive decline. He makes a compelling case for why the timing and quality of these interventions could matter as much as diet itself.

Finally, this episode goes beyond individual health to consider public health implications, particularly the need for better regulation in the supplement industry and enhanced nutritional education for medical practitioners.

Timestamps

[01:20] Professor Nolan's academic journey and early inspirations in vision science
[02:12] Groundbreaking research on age-related macular degeneration (AMD)
[04:24] How carotenoids contribute to eye health and disease prevention
[07:27] Expanding from eye research to exploring brain health connections
[16:23] Overcoming challenges in developing effective nutritional supplements
[20:57] The role of preventative nutrition in eye and cognitive health
[27:28] Key findings from major human trials on carotenoids and vision
[33:37] Evidence linking carotenoids to cognitive health and aging
[42:53] Practical insights for medical practitioners on using nutrition for eye health

Links:

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Caretenoid supplement mentioned by Prof. Nolan: MacuPrime

#542: Nutrients for Cognitive Performance in Sports – Prof. Shawn Arent, PhD Nov 12, 2024

Show notes

In the world of sports nutrition, understanding how different supplements and nutrients impact not just physical performance but also cognitive function is rapidly gaining traction. Athletes are constantly seeking that competitive edge, and while many are familiar with the benefits of carbohydrates and caffeine for energy and focus, there's much more at play.

Emerging research is highlighting the roles of compounds like creatine and omega-3s, not only for muscle recovery but also for brain health, particularly following traumatic brain injuries (TBI).

Beyond the usual suspects of performance nutrition, intriguing compounds like theacrine and tyrosine are entering the conversation. With potential cognitive effects that range from improved focus to faster decision-making, these supplements have sparked interest but also raise questions.

How strong is the evidence behind these claims, and where do we draw the line between scientific promise and practical application? How do we apply the science in real-world settings where perfect data may not exist?

This episode addresses these questions via the insights of Professor Shawn Arent of University of South Carolina.

Timestamps

01:44 – Dr. Arent's key areas of research
04:03 – Defining and understanding cognitive performance in athletes
09:31 – The impact of carbohydrates on cognitive function and decision-making
29:00 – Protein, amino acids, and their role in cognitive function under stress
34:17 – How caffeine enhances cognitive performance: decision-making and reaction time
42:00 – Comparing the effects of theacrine and caffeine on cognitive and physical performance
44:48 – How caffeine dosing impacts sleep and recovery
46:55 – Theacrine, dynamine, and emerging supplements in sports performance
57:56 – Nicotine's potential cognitive benefits and the associated risks for athletes
01:04:56 – Creatine and omega-3s: their roles in brain health and concussion recovery
01:13:05 – Navigating the challenges of applying research to real-world practice

Links:

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Get research reviews from Dr. Eric Trexler and collegues

#541: Lean Mass Hyper Responders & the Lipid Energy Model: Do the Claims Stand Up to Scrutiny? Nov 05, 2024

Show notes

When discussing cardiovascular health, few topics stir as much debate as cholesterol, particularly in relation to low-carb and ketogenic diets. Recently, there's been significant attention given to a proposed model that suggests high LDL cholesterol may not pose the same cardiovascular risk in certain individuals, specifically those labeled as "lean mass hyper-responders." This raises important questions: Is it possible that high cholesterol might not be dangerous for everyone? Or are we witnessing a dangerous misinterpretation of the science?

In this episode, we break down the ideas behind the "lipid energy model" and explore how it has been framed in the context of low-carbohydrate and ketogenic diets. While proponents claim this model sheds light on how some people can have elevated LDL without increasing heart disease risk, critics warn that miscommunication and oversimplification of these ideas are leading many down a dangerous path. With real-world health decisions hanging in the balance, it's crucial to carefully examine what the science truly says about cholesterol, inflammation, and heart disease.

Join us as we dive into the evidence with Dr. Gary McGowan. We'll dissect what the current research supports, what remains speculative, and how social media has amplified both the promising and problematic aspects of this model. If you've ever wondered about the impact of high cholesterol on heart disease risk in the context of ketogenic or low-carb diets, this episode is essential listening.

Timestamps

02:27 What are the "Lean Mass Hyper Responder" phenotype and the "Lipid Energy Model"
27:29 Looking at recent publications and the "KETO Trial"
47:06 Public communication and misinterpretation
51:18 Clinical implications of diet-induced dyslipidemia
55:14 Responsibility in scientific communication
57:30 Real-world examples of poor communication or misinterpretation
01:13:27 Ethical concerns with the promotion of the model
01:25:59 Final thoughts

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Find Dr. McGowan at:
- Triage Method
- Instagram: @drgarymcgowan
Papers discussed in this episode:

Fasting for Health: What Do We Know? (SNP34) Oct 29, 2024

Show notes

Fasting has gained immense popularity as a dietary approach, but what does the scientific evidence say about its health benefits?

Studies have explored how fasting might influence metabolic markers, energy expenditure, and even aging. However, while fasting shows promise in some animal models, translating these effects to humans is less clear.

A key part of the debate centers on whether fasting offers unique health advantages or whether its benefits stem primarily from reduced calorie intake. Time-restricted eating and intermittent fasting protocols show promise in regulating appetite and reducing energy intake, potentially leading to weight loss. But, when calories are controlled, does fasting still improve health independently?

This episode explores the evidence to determine if fasting confers metabolic advantages over non-fasting diets. In addition, we'll take a look at its impact on behavioral patterns and ask if that could play a pivotal role in promoting better health outcomes.

To listen to this episode in full, subscribe to Sigma Nutrition Premium.

Timestamps: