Sigma Nutrition Radio

Links: Go to episode pageSubscribe to PremiumJoin the Sigma email listGo to our recommended resources About This Episode: Have you ever wondered how exercise affects our appetite and energy intake? While we know that single bouts of exercise can create a short-term energy deficit, do they also influence our hunger levels? And what about long-term exercise training? Could it modify our appetite in ways that help us better control our weight? Recent research suggests that exercise may indeed play a role in appetite regulation. Could exercise modify the subjective and homeostatic mediators of appetite in ways that enhance our feelings of fullness after a meal? One of the most fascinating aspects of this research is the variability in responses between individuals. Why do some people experience changes in appetite and energy intake after exercise, while others don’t? Could factors like adiposity, sex, or habitual physical activity levels play a role? In this episode, Dr. James Dorling of the University of Glasgow helps us delve into the evidence surrounding how factors like adiposity, sex, and habitual physical activity modulate our responses to exercise in terms of appetite, energy intake, and appetite-related hormone responses. About The Guest: Dr. James Dorling is a lecturer in Human Nutrition at the University of Glasgow. Dr. Dorling’s research is broadly focused on three areas: (1) the impact of nutrition and physical activity interventions on obesity-related endpoints and biomarkers of aging; (2) the regulators of appetite and eating behaviours; and (3) the changes in appetite and eating behaviours in response to health interventions. During his PhD, he studied the effects of acute exercise and obesity-related single nucleotide polymorphisms on appetite and appetite-related hormones. Following this, Dr. Dorling joined Pennington Biomedical Research Center where he worked as a postdoctoral researcher. His postdoctoral research principally focussed on the influence of calorie restriction and physical activity on weight, markers of aging, and eating behaviours.

In a world flooded with claims, advice, and recommendations on how to extend our lifespan, the buzz around various diet approaches, supplement regimens, and lifestyle hacks is deafening. But amidst the noise, one must pause to ponder: Are these claims rooted in science? And perhaps more crucially, are we even asking the right questions or pursuing the correct goals in our quest for longevity? Join us in our upcoming podcast episode as Danny delves into these intriguing questions. Rather than getting lost in the sea of trends and fads, Danny offers his insights on the essential inquiries we should be making. Discover how to shift our focus towards the core factors that genuinely enhance our chances of leading longer, healthier lives. Don’t miss out on this thought-provoking exploration into the science and philosophy behind longevity. Links: Subscribe to PremiumGo to SigmaNutrition.com

Acronyms & Terminology: NHSCAMHS eating disorder unitTier 4 ServicesNG FeedMDT decisionCBT-EARFIDSSCM Links: Subscribe to PremiumGo to episode page About This Episode: When exploring the landscape of eating disorder treatment and research, several crucial topics emerge, each shedding light on different aspects of this complex field. Firstly, the practice of nasogastric feeding under restraint raises ethical questions and considerations. How do healthcare professionals navigate the balance between ensuring adequate nutrition and respecting the autonomy and dignity of patients? What are the potential implications and risks associated with this practice? Progress in understanding and treating eating disorders has evolved significantly over the years, yet challenges persist in translating research findings into effective clinical practice. How can advancements in genetics, neurobiology, and psychology inform more personalized and holistic treatment approaches? What barriers hinder the implementation of evidence-based practices within healthcare settings? An essential aspect of eating disorder treatment is understanding what “recovery” truly means. Beyond weight restoration, what factors contribute to a meaningful and sustainable recovery journey? How can healthcare professionals support individuals in achieving their unique goals and aspirations for recovery? Improving services and introducing better treatment options requires a nuanced understanding of the complexities inherent in eating disorders. How can healthcare systems prioritize patient-centered care and tailor interventions to meet the diverse needs of individuals affected by eating disorders? What strategies can be employed to address systemic challenges and foster positive change within healthcare settings? In addressing these questions and navigating the complexities of eating disorder treatment and research, expertise and insights from seasoned professionals are invaluable. In this episode Helen West, an Advanced Specialist Eating Disorders Dietitian with over 12 years of clinical experience, discusses her experience and understanding of these areas. With her extensive background and expertise, Helen offers valuable perspectives in tackling these critical topics within the realm of eating disorder treatment and research.

Links: Course:Applied Nutrition LiteracySubscribe to PremiumGo to episode page About This Episode: There has been much debate about the role of nutritional reductionism in research. This approach generally aims to study diet’s effects by breaking down the intricate web of dietary factors into smaller, more manageable components. But critics have asked does this approach truly capture the full picture of nutrition’s influence on our well-being? In an attempt to help answer research questions there has been a proposal for the use of “nutritional geometry”, a framework that delves into the multidimensional relationships between nutrients and their effects on organisms. Within this framework, the protein leverage hypothesis emerges, proposing that our bodies prioritize protein intake and adjust food consumption accordingly. But how does this theory fit into the broader spectrum of nutrition science, and what implications does it hold for understanding and managing our diets? Additionally, as aim to do better nutrition research, we are met with philosophical questions that challenge traditional reductionist views. Is it enough to simply dissect foods into their nutrient components, or do we need a more holistic understanding of dietary patterns and their impact on health? In this episode, Prof. David Raubenheimer and Dr. Jonathan Sholl discuss the need to have an approach where science meets philosophy, and where reductionism meets synthesis. And we dive into ideas they have proposed that make a defense of some aspects of reductionism.

Links: Enroll in our new course!Go to episode pageSubscribe to Sigma Nutrition Premium About This Episode: Sigma Nutrition is ten years old this week! Over this time, I’m grateful for a wealth of insights garnered from interviews with some of the brightest minds in the field of evidence-based nutrition science. Through these conversations, I’ve come to understand the critical underpinnings of scientific thinking, the importance of honing our critical appraisal skills, and the crucial distinction between accurate dissemination of information and misleading “half-truths”.

Links: Applied Nutrition LiteracyEpisode page About This Episode: Navigating the vast landscape of research literature, particularly in the realm of nutrition science, presents numerous challenges for readers seeking to extract meaningful insights. Before diving into research papers, individuals should have a precise understanding of the specific questions they seek to address. Without this clarity, there is a risk of wasting time on irrelevant studies or misinterpreting findings. Furthermore, the selective approach to sourcing research is crucial. With countless studies available, employing heuristic strategies to filter out irrelevant ones and prioritize those aligned with research goals is essential. Effectively reading nutrition studies requires a nuanced understanding of statistical concepts and methodologies used in various studies. Developing this understanding can be challenging, especially for individuals without a background in statistics or research methodology. In this episode, we discuss all these issues. Course syllabus: Applied Nutrition Literacy

Join the email list here. Applied Nutrition Literacy Core Modules: Enrollment opens on Wednesday March 27.

Questions Answered in This Episode: [01:22][14.56][26.20][40.09][44.10][49.53][55.26] This is a preview of is one of our Premium-exclusive AMA (ask me anything) episodes, where we answer questions submitted by Premium subscribers. To listen to the full episode, you’ll need to be a Premium subscriber and access the episode on the private Premium feed.

Links: Go to episode pageSubscribe to PremiumSee recommended resourcesReceive the Sigma email newsletter About This Episode: The question of whether dietary fat quality causally affects atherosclerosis risk has been a subject of extensive research and debate within the field of nutrition and cardiovascular health. Atherosclerosis, the build-up of plaque in arteries, is a key factor in the development of cardiovascular diseases, including heart attacks and strokes. Traditionally, dietary fat has been implicated in contributing to atherosclerosis, with a focus on reducing overall fat intake. However, recent studies have shifted the focus towards the quality of dietary fats rather than their quantity. Not all fats are created equal, and researchers are now paying closer attention to the types of fats consumed in the diet. Saturated fats, commonly found in animal products and some tropical oils, have long been associated with increased cholesterol levels and atherosclerosis. On the other hand, unsaturated fats, including monounsaturated and polyunsaturated fats found in olive oil, nuts, and fish, have been linked to potential cardiovascular benefits. Research suggests that replacing saturated fats with unsaturated fats may have a positive impact on blood lipid profiles and reduce the risk of atherosclerosis. Additionally, genetic factors and individual responses to different fats may play a role in how dietary fats impact atherosclerosis risk. In this episode, Dr. Jacob Christensen discusses the research in this area and some conclusions about whether we can say dietary fat quality causally increases atherosclerotic cardiovascular disease (ASCVD) risk. This includes looking at the relationship between low-density lipoprotein (LDL) particles and ASCVD, the link between dietary fat quality and LDL particles, and then finally the relationship between dietary fat quality, LDL particles, and ASCVD. About the Guest: Jacob J. Christensen is a clinical dietitian and researcher at University of Oslo. His research interests include cardiovascular diseases, lipid metabolism, nutrition, genomics and data science.

Links: Go to episode pageSubscribe to PremiumJoin the Sigma mailing listSigma's Recommended Resources About This Episode: There is a lot of interesting research going on related to plant-derived fatty acids, owing to their potential to help improve health and provide sustainable alternatives to other sources of healthy-promoting fatty acids. In addition to work looking at the long-investigated alpha-linolenic acid (ALA), some research is now starting to look at more novel fatty acids like stearidonic acid (SDA), and pinolenic acid (PLA), each presenting unique structures and potential benefits within various plant sources. One intriguing focal point is Ahiflower oil, a distinctive source that harbors both ALA and SDA. In this episode, Dr. Ella Baker of the University of Southampton discusses some of the science behind plant-derived fatty acids, offering a deeper understanding of their distinctive qualities, conversion pathways, and the captivating interplay between omega-3 and omega-6 fatty acids. Dr. Baker’s research to date focuses on the metabolism, functionality, and underlying mechanisms of action of plant-derived fatty acids. Her interests include novel plant-derived fatty acids and exploring the effects on membrane structure and function.

Links: Go to episode pageSubscribe to PremiumSigma's recommended resourcesJoin our email newsletter for free About This Episode: Kidney stones, crystalline deposits formed within the kidneys, present a formidable challenge to individuals grappling with their debilitating effects. These mineral accumulations, though small in size, can inflict significant pain and discomfort as they navigate through the urinary tract. Understanding the nuances of dietary management and treatment for kidney stones is crucial for those seeking relief and prevention. What makes this subject particularly intricate is the diversity of kidney stones – a mosaic of compositions ranging from calcium oxalate to uric acid. Recognizing that not all kidney stones are created equal, dietitians and renal specialists tailor their recommendations to address the specific nature of the stones, unveiling a spectrum of dietary strategies that aim to alleviate symptoms and impede the recurrence of these insidious formations. In this episode, specialist renal dietitian Deepa Kariyawasam brings us through the main causes of kidney stones, the potential dietary interventions, and how to guide individuals toward personalized pathways for kidney stone management.

Acronyms: About This Episode: Dietary Reference Intakes (DRIs) are a set of nutrient reference values, developed in the US, that are used to assess and plan the nutrient intake of healthy individuals. They provide guidelines for the recommended amounts of various nutrients to maintain health and prevent deficiencies or excesses. Different countries may have their own sets of dietary reference values or guidelines that serve similar purposes but may be named differently. DRIs include several different reference values: DRIs play a crucial role in nutrition and public health for several reasons. DRIs provide specific recommendations for the intake of essential nutrients, helping individuals and health professionals understand the amounts needed to maintain good health. By establishing RDAs and ULs, DRIs help prevent nutrient deficiencies and toxicity, ensuring that individuals consume an appropriate range of nutrients. Governments and health organizations use DRIs to develop public health policies, nutrition programs, and guidelines for food fortification to improve the overall health of populations. For nutrition professionals, understanding DRIs is essential as it forms the basis for assessing and planning dietary recommendations for individuals and populations. Note: This episode is one of our Premium-exclusive episodes. To listen to the full episode, you’ll need to be a Premium subscriber and access the episode on the private Premium feed. Otherwise, you can hear a preview of the episode above or on the public feed of the podcast. Links: Go to episode pageSubscribe to Sigma Nutrition Premium

Links: Go to episode page (with episode resources)Subscribe to PREMIUMGet the Sigma email newsletterSee Sigma's recommended resources About This Episode: Alzheimer’s disease has a profound impact on individuals, families, and societies worldwide. As a progressive neurodegenerative disease, it not only robs individuals of their cognitive abilities but also places an immense emotional and economic burden on caregivers. Mechanistically, the causes of Alzheimer’s are incredibly complex and not fully understood. And in terms of treatment, the landscape appears challenging. Drug discovery efforts for dementias, including Alzheimer’s, have faced setbacks, leaving a void in effective treatments. Consequently, attention has shifted toward preventive strategies, including dietary patterns. From a prevention standpoint, both genetics and lifestyle should be considered. Which throws up many interesting questions… To what extent do genetic factors contribute to Alzheimer’s risk compared to lifestyle choices, and how does this interaction influence disease development? What role does lifestyle play in Alzheimer’s risk, and is there evidence supporting the influence of specific nutrients on cognitive health? How do diet patterns impact Alzheimer’s risk? Are there discernible risk differences associated with specific dietary choices, and how do these interact with genetic factors, such as the ApoE genotype? In this episode, Drs. Ayesha Sherzai and Dean Sherzai are on the podcast to answer these questions and discuss this topic in more depth. About The Guests: Dr. Ayesha Sherzai is a neurologist and co-director of the Alzheimer’s Prevention Program at Loma Linda University, where she leads the Lifestyle Program for the Prevention of Neurological Diseases. She completed a dual training in Preventative Medicine and Neurology at Loma Linda University, and a fellowship in Vascular Neurology and Epidemiology at Columbia University. She is also a trained plant-based culinary artist. Dr. Dean Sherzai is co-director of the Alzheimer’s Prevention Program at Loma Linda University. Dean trained in Neurology at Georgetown University School of Medicine, and completed fellowships in neurodegenerative diseases and dementia at the National Institutes of Health and UC San Diego. He also holds a PhD in Healthcare Leadership with a focus on community health from Andrews University.

Links: Go to episode page (with episode resources)Subscribe to PremiumReceive the Sigma Nutrition newsletter About This Episode: Numerous nutrition studies present findings of “no effect,” but interpreting such results requires caution. A null finding, indicating an absence of impact from a nutrient or exposure, may not necessarily suggest a lack of effect overall. Instead, it could stem from issues related to the study’s design, the nature of the exposure, or participant characteristics. We’ve often referred to such studies as being “null by design”. These studies, often termed “null by design,” may yield inconclusive results due to insufficient contrast in exposure levels to reveal a significant effect size. Additionally, participants’ baseline nutrient status or intake can contribute to false negatives. For instance, if a study provides a nutrient to individuals already replete in that nutrient, it may lead to an erroneous conclusion. This phenomenon can be understood by considering the bell curve of activity for a nutrient. Moreover, a lack of methodological rigor can generate ‘false negatives.’ If previous literature indicates associations between high intake of a specific food or nutrient and certain outcomes, a study comparing levels of intake well below that threshold may produce a misleading result. Some challenges arise from an overly reductionist perspective. In disease processes, reductionism simplifies diseases to a single primary source at the cellular and molecular level. This perspective assumes that if a nutrient shows a relationship with health or disease outcomes at a population level, its biological activity should manifest in isolation. However, applying such assumptions to exposures like diet may not be tenable. In this discussion, we delve into the concept of “null by design” and present three specific studies with null findings, emphasizing the need for careful interpretation.

Links: Go to episode page (with supporting links/resources)Subscribe to PREMIUMLearn more about Sigma NutritionCrushing Comparisons course About This Episode: Social comparison theory, developed by psychologist Leon Festinger in the 1950s, posits that individuals determine their own social and personal worth based on how they stack up against others. This theory suggests that people engage in social comparisons to evaluate their abilities, opinions, and attributes, often choosing relevant others for comparison. In the realm of body image and self-perception, social comparison theory becomes particularly pertinent, as individuals tend to assess their own bodies in relation to societal ideals and the bodies of others. This process of comparison can have profound implications for body dissatisfaction and the development of disordered eating patterns. This raises thought-provoking questions about the impact of social comparison theory on body image and eating behaviors. In this episode, Shannon Beer explores these questions and offers valuable insights into the complex interplay between societal influences, individual perceptions, and the development of body dissatisfaction and disordered eating. About The Guest: Shannon Beer is a registered nutritionist, health and confidence coach and certified Compassionate Mind Training facilitator. Shannon works with people aiming to improve their health through facilitating lasting behaviour change in their approach to diet, exercise and body image. She has developed a coaching framework that applies motivational interviewing, cognitive behavioral coaching, and acceptance and commitment therapy-aligned processes in a client-centered alliance toward their own values-based goals.

Questions Answered in This Epsiode: [02:16][15:25][24:36][33:25][41:39][46:35][51:58][55:21] Note: This is a Premium-exclusive “ask me anything” episode. You can access the full episode as a Premium subscriber. Join here.

Links: Go to episode pageSubscribe to PremiumSigma's recommended resourcesBite Me Nutrition – Australia@jonosteedman@dannylennon_sigma About This Episode: There is no shortage of misleading, confusing and even dangerous nutrition information on the internet. And, unfortunately, much of it can sound very convincing and appealing to people who wish to improve their health. The result can be that they may end up ironically doing the opposite. At an individual level, dietitians and medical practitioners end up having to work with patients who have heard incorrect information or who have been following poor advice. What issues does this present? What is the most productive way to help patients and clients in this situation? How can we help give better information while also listening and caring for the patient? To discuss such questions, dietitian Jonathan Steedman is on the podcast to share his experiences and approaches to spreading evidence-based information in a palatable and productive manner. About The Guest: Jonathan Steedman is an Acredited Practising Dietitian (APD) in Australia. He currently works with patientes via telehealth services. He is well-known on social media for explaining confusing nutrition topics in a way that is understandable and engaging for the general population.

Links: Go to episode page (with study links)Subscribe to PremiumSigma's recommended resourcesGet our weekly email newsletter About This Episode: Insufficient energy availability can significantly disrupt normal hormonal, metabolic, and physiological processes, prompting the body to initiate a coordinated response aimed at conserving energy. While commonly viewed as beneficial for weight loss and managing cardiometabolic conditions in the current obesity epidemic, chronic energy deficiency in the context of modern sports and exercise nutrition is linked to adverse health outcomes and diminished athletic performance. Nevertheless, the evidence regarding the negative impact of energy deficit on physical capacity and sports performance is not entirely clear. Although severe energy deficiency can impair physical capacity, it’s noteworthy that humans can enhance aerobic fitness and strength even in the presence of significant energy deficits. Strikingly, many elite athletes compete at the highest levels despite displaying evident signs of energy deficiency. This raises intriguing questions about how the human body adapts to energy deficits, challenging conventional views on the relationship between energy availability and athletic prowess. To discuss some potential reasons for this ability to maintain peak physical performance while suppressing energetically demanding physiological traits, researcher Dr. Jose Areta of LJMU is on the podcast to discuss his work in this area. About The Guest: Dr. José Areta currently works as a lecturer in Sports Nutrition and Metabolism at the School of Sport and Exercise Sciences at LJMU. José’s primary interest is in the area of training-nutrient interactions in humans. In other words, he investigates how to manipulate ingestion of carbohydrates, fat and protein around training to optimise physical performance and health. The outputs of his research have not only expanded the knowledge of the field but had significant impact and influence on determining current dietary recommendations and practices world-wide. His work has provided novel insights in relation to the amount, timing, quantity and distribution of carbohydrates, fat and protein and dietary supplements around training. Over the last few years José has been developing his research in the area of the endocrinological, metabolic and physiological effects of energy restriction, in which he is currently growing his research team and capability.

Links: About This Episode: The Portfolio diet is a nutritional approach that has garnered attention for its ability to reduce blood lipids and thus improve cardiovascular health. While past intervention trials have demonstrated significant reductions in blood lipids, a critical aspect often overlooked is the long-term impact, both in terms of adherence and disease outcomes. A recent study aimed to address this by looking at disease risk across three cohorts: the Nurses’ Health Study I, Nurses’ Health Study II, and the Health Professionals Follow-up Study. The study made use of a Portfolio Diet Score (PDS), a comprehensive metric that evaluates the diet’s efficacy based on specific components. These components include positive rankings for plant proteins (especially from legumes), nuts and seeds, viscous fiber sources, phytosterols (mg/day), and plant monounsaturated fat sources. Conversely, the PDS negatively ranks foods high in saturated fat and cholesterol. In this episode, Dr. Andrea Glenn, the lead author of this study, discusses the intricacies of the research, providing insights into its findings and shedding light on how these findings resonate within the broader landscape of literature.

This episode is one of our Premium-exclusive AMA (ask me anything) episodes, where we answer questions submitted by Premium subscribers. To listen to the full 90 minute episode, you’ll need to be a Premium subscriber and access the episode on the private Premium feed. Otherwise, you can hear a preview of the episode here. Full List of Questions: [01:50] [22.10] [29.10] [40:45] [50:13] [59:32] [01:08:48]