Sigma Nutrition Radio

Danny Lennon
Sigma Nutrition Radio

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. 1 DAY AGO

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

    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: Go to episode page Join the Sigma email newsletter for free Subscribe to Sigma Nutrition Premium Enroll in the next cohort of our Applied Nutrition Literacy course Get research reviews from Dr. Eric Trexler and collegues

    1h 23m
  2. 5 NOV

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

    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 Related Resources Go to episode page Join the Sigma email newsletter for free Subscribe to Sigma Nutrition Premium Enroll in the next cohort of our Applied Nutrition Literacy course Find Dr. McGowan at: Triage Method Instagram: @drgarymcgowan Papers discussed in this episode: Norwitz et al., 2022 – The Lipid Energy Model: Reimagining Lipoprotein Function in the Context of Carbohydrate-Restricted Diets Norwitz et al., 2021 – Elevated LDL Cholesterol with a Carbohydrate-Restricted Diet: Evidence for a “Lean Mass Hyper-Responder” Phenotype KETO Trial: Budoff et al., 2024 – Carbohydrate Restriction-Induced Elevations in LDL-Cholesterol and Atherosclerosis

    1h 30m
  3. 29 OCT

    Fasting for Health: What Do We Know? (SNP34)

    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: [00:54] Defining fasting [03:44] Historical context and early research [08:01] Mechanisms and claims of fasting [18:15] Types of fasting protocols [22:18] Time-restricted eating and chronobiology [28:29] Energy expenditure and behavioral changes [36:53] Fasting vs. weight loss: independent benefits [41:47] Health markers and weight loss outcomes [43:37] Muscle mass concerns during fasting [47:31] Animal models vs. human studies [51:29] InterFAST study insights [01:00:37] Behavioral vs. metabolic changes [01:11:25] So what do we know? Links: Subscribe to Sigma Nutrition Premium Join the Sigma email newsletter for free Enroll in the next cohort of our Applied Nutrition Literacy course Go to the page for this episode

    21 min
  4. 22 OCT

    #540: How Can We Improve Body Image and Self-Esteem Without Physique Change? – Gabrielle Fundaro, PhD & Eric Trexler, PhD

    Body image and self-worth are deeply intertwined concepts that influence how we see ourselves and interact with the world. Many people believe that changing their physique is the key to improving their body image, but is it really that simple? This connection between appearance and self-esteem raises important questions about how we define confidence and whether our sense of worth should be tied to how we look. Our relationship with food plays a crucial role in how we view ourselves. While some see food as fuel, others attach much more significance to their eating habits, often linking dietary choices to discipline, success, or failure. But what happens when these beliefs become too rigid? Understanding how our perceptions of food and body image are shaped is essential for navigating the balance between health, happiness, and personal fulfillment. Physique change, often seen as a positive goal, can bring about unexpected psychological impacts. Pursuing a leaner or more muscular body might boost temporary feelings of confidence, but could it also reinforce negative patterns of thought? In an episode co-hosted with Dr. Eric Trexler, Danny talks with Dr. Gabrielle Fundaro in order to tackle some of these concepts and questions. Timestamps: [04:54] Start of conversation [06:40] Defining body image and self esteem [12:26] Relationship with food and weight controllability beliefs [20:38] Impact of body composition on body image [27:40] Challenges in changing body image perceptions [34:43] Influence of coaches on client body image [41:57] Screening for disordered eating [51:50] Ethical responsibilities of fitness professionals [54:53] Improving body image without physique change [61:02] Key ideas segment (premium-only) Links: Join the Sigma email newsletter for free Subscribe to Sigma Nutrition Premium Get more of Dr. Trexler’s research analysis with the MASS Research Review Related previous episodes: See episodes 484 and 367

    1h 1m
  5. 15 OCT

    #539: How Does Carbohydrate Availability Impact Resistance Training? – Cliff Harvey, PhD & Eric Helms, PhD

    Some suggest that, since individual lifts or short-duration efforts don’t rely heavily on glycogen, carb intake might not be critical for strength athletes. If glycogen depletion isn’t a pressing issue, could athletes thrive on lower-carb diets without sacrificing performance? Or could there be overlooked benefits to having greater carbohydrate availablily in those sessions? In strength sports and resistance training, do carbohydrates play an important role or not? Are carbohydrates really necessary for resistance training? How does training volume, intensity and goals impact the carbohydrate requirement? In this episode, Dr. Cliff Harvey and Dr. Eric Helms offer their perspectives on this interesting and practically important issue. Timestamps: [00:03:40] Do carbohydrates have a role in resistance training? [00:12:23] Do individuals respond differently? [00:18:25] Recent research insights [00:35:08] Carbohydrate “sensing” and performance [00:47:17] How to think about carbohydrate needs [00:54:06] Changing views on nutrient timing [01:06:37] Ketogenic diets and muscle gain [01:22:02] Dietary patterns and health – Are macronutrients that important? [01:31:42] Key ideas segment (Premium-only) Links: Subscribe to Premium for study notes and transcript Receive the email newsletter for free Join the waitlist for our Applied Nutrition Literacy course Sports Nutrition Association Get more of Dr. Helm’s research analysis with the MASS Research Review SigmaNutrition.com

    1h 33m
  6. 8 OCT

    #538: Can Fish Oil Supplementation Increase Risk of Irregular Heart Rhythms?

    Omega-3 fatty acids are often viewed as beneficial or, at worst, neutral supplements when it comes to supporting cardiovascular health, lowering triglycerides, and offering anti-inflammatory effects. Much of the focus in recent years has centered on understanding how significant these benefits are, particularly for heart health, with many studies highlighting the potential for omega-3s to play a positive role in reducing cardiovascular risk. However, an emerging concern has complicated the conversation around omega-3 supplementation. Several large trials, including the REDUCE-IT and STRENGTH trials, have suggested that omega-3 supplementation might be linked to an increased risk of atrial fibrillation (AF), a common cardiac arrhythmia characterized by an irregular and often rapid heart rate. These findings have sparked debate over whether omega-3s could contribute to this potentially serious heart condition, leaving clinicians and health-conscious individuals uncertain about the safety of these supplements. However, not all the research supports this elevated risk. This discrepancy raises important questions about how we interpret the data from various studies, the design of those trials, and whether other factors might be influencing these results. Understanding this issue in depth is crucial for making informed decisions about omega-3 supplementation and its potential risks and benefits. In this episode we walk through the studies and the key points to consider. Timestamps: 00:30 Updates on Alan’s upcoming study 05:06 Atrial Fibrillation and Omega-3 14:52 RCTs and AFib: Key Studies 29:14 Meta-Analyses and Dose-Response 46:46 Practical Implications and Recommendations 53:53 Key Ideas Segment (Premium-only) Links: Join the Sigma email newsletter for free Subscribe to Sigma Nutrition Premium Go to episode page

    55 min

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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.

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