Explorez tous les épisodes du podcast Sigma Nutrition Radio
| Titre | Date | Durée | |
|---|---|---|---|
| #583: Ultra-Processed Foods & Fixing the Food Environment – Kevin Hall, PhD | 11 Nov 2025 | 00:54:33 | |
Ultra-processed foods have become central to the way we eat and to many of the challenges we face in public health nutrition. They dominate supermarket shelves, shape population diets, and often appear as the prime suspect in rising obesity and metabolic disease rates. But beyond the label itself, what exactly makes these foods problematic? Is it their nutrient composition, their texture and palatability, the rate at which we consume them, or the broader environments that make them so accessible and appealing? The debate around ultra-processed foods sits at the intersection of metabolic science, behaviour, and policy. It raises uncomfortable questions about how food systems evolved to prioritise convenience and profit, and what it might take to meaningfully change that trajectory. In this episode, Dr. Kevin Hall joins the podcast to examine the evidence from controlled feeding studies and population research, exploring what we really know about ultra-processed foods, overeating, and how we might begin to fix the food environment. Timestamps
| |||
| SNP45: Antioxidants – What You Need To Know | 04 Nov 2025 | 00:13:47 | |
This is a Premium-exclusive episode of the podcast. To listen to the full episode you need to be subscribed to Sigma Nutrition Premium. What exactly are "antioxidants," and why do they get so much hype? We often hear that blueberries, dark chocolate, and red wine are healthy because they're packed with antioxidants – but is the story really as simple as "more antioxidants = better health"? In this episode, Danny explores the true role of antioxidants in the body, challenging simplistic narratives. Are antioxidants magic molecules that single-handedly prevent aging and disease? Or is the reality more nuanced, with context and balance being key? We delve into these intriguing questions to clarify what antioxidants are, how they work, and what the current consensus tells us about using them for health. Antioxidants are frequently credited as the reason why colorful fruits and vegetables are beneficial. Yet, as past Sigma episodes on polyphenols have noted, the benefits of those plant foods aren't primarily due to direct antioxidant effects. Here we untangle common misconceptions (e.g., "antioxidants = health, always"), distinguish between different types of antioxidants, and explain why simply taking high-dose antioxidant supplements isn't a guarantee of protection – and in some cases might even backfire. By the end, health professionals and science-savvy listeners will understand the diverse roles of antioxidants, the importance of balance, and how to apply this knowledge in practice. Timestamps
Links & Resources:
| |||
| #575: How Does Dairy Impact Cardiometabolic Health? – Prof. Jean-Philippe Drouin-Chartier | 02 Sep 2025 | 00:46:12 | |
Dairy is often treated as a single food group, yet milk, yogurt, cheese, and butter can have very different effects on health. Some evidence links yogurt to favourable outcomes, while butter is known to raise LDL cholesterol. And then there's the paradox of cheese: high in saturated fat, but not consistently associated with higher heart disease risk. These complexities raise the question of whether the "dairy matrix" (the combination of nutrients and food structure) explains why not all dairy acts the same. In this episode, Prof. Jean-Philippe Drouin-Chartier, a nutrition researcher and registered dietitian, is on the show to examine what recent trials and large population studies tell us about dairy foods and cardiometabolic health. The discussion covers blood lipids, blood pressure, glucose metabolism, and how guidelines should interpret this evolving evidence. Timestamps
| |||
| #503: Lyon Diet Heart Study – Canola Oil, "Mediterranean" Diets & Minimizing Bias | 28 Nov 2023 | 00:43:04 | |
Links: About This Episode: The Lyon Diet Heart Study (LDHS) is often cited as one of the pivotal studies that helped establish the Mediterranean diet as a recognized and recommended dietary pattern for cardiovascular health. A clinical trial conducted in Lyon, France, the LDHS showed significant reduction in cardiac death could be achieved in secondary prevention patients using a dietary intervention. Conducted between 1992 to 1996, the study involved 605 participants who had previously experienced a heart attack (myocardial infarction). LDHS showed an incredible 75% lower risk of cardiac death in these patients. This remarkable reduction was unexpected and led to considerable attention from the medical and scientific communities. LDHS is interesting to dig into for several reasons. First, it's clever methodology was able to account for some challenges of doing nutrition research. Second, the dietary intervention, whilst named as a "Mediterranean diet", should perhaps be considered differently. In this episode, Alan and Danny dig into all the details, highlighting some important lessons we can take from LDHS. | |||
| #502: Sydney Diet-Heart Study – Is Linoleic Acid Causing Heart Disease? | 21 Nov 2023 | 00:40:52 | |
Links:
About This Episode: The Sydney Diet-Heart Study was a clinical trial conducted in the 1960s and 1970s that aimed to examine the hypothesis that reducing saturated fat intake in the diet would lead to a reduced risk of heart disease. However, it really only gained attention after a more recent re-analysis by Ramsden et al., which in recent years has been used as supporting evidence for the idea that increased polyunsaturated fat (PUFA), and specifically linoleic acid, in addition to reduced saturated fat intake, can increase heart disease risk. This was based on the findings that substituting linoleic acid in place of saturated fat increased all-cause, CVD and CHD mortality. This is of course counter to prevailing consensus and guidelines in this area, which routinely show reduced risk on replacing SFA with PUFA. Could this trial undermine the common conclusions that replacing saturated fat with polyunsaturated fat decreases heart disease risk? In this episode Alan and Danny discuss some of the crucial aspects to understand about this study and what it means for what conclusions can be made about the impact of PUFA broadly, and linoleic acid specifically, on our health. | |||
| Addressing Some Criticisms of Nutritional Epidemiology (SNP 23) | 14 Nov 2023 | 00:10:38 | |
Note: This is a Premium-exclusive episode, so in order to listen to the full episode you'll need to subscribe to Sigma Nutrition Premium. About This EpisodeNutritional epidemiology has faced strong criticism over time. While some of the methodological limitations are fair, often there are criticisms that are misguided and inaccurate. In this episode, Danny touches on a few examples of the misunderstandings of the field and how such claims can be addressed in a more accurate manner. Links: | |||
| #501: Sex-based Training Recommendations: Evidence-based or Hype? – David Nolan, PhD | 07 Nov 2023 | 01:13:29 | |
Links:
About This Episode: The field of research exploring sex differences in exercise response has yielded intriguing findings, shedding light on the complex interplay between biology, physiology, and training adaptations. One of the fundamental areas of investigation pertains to sex disparities in strength, power, and hypertrophy. Historically, it's been well-established that males, on average, exhibit greater absolute strength and muscle mass compared to females. This discrepancy often traces its roots back to inherent physiological distinctions. However, when it comes to responses to strength and hypertrophy training, the narrative becomes more nuanced. Research indicates that, when individuals of both sexes follow matched resistance training protocols, the relative improvements in strength and hypertrophy are quite similar. So, do women need to be trained differently than men? The answer, it appears, is not as much as one might assume. The principles of progressive overload, specificity, and other training fundamentals remain constant. While individualization is key, the idea of drastically distinct training guidelines based on sex lacks compelling empirical support. The guest in this episode, Dr. David Nolan, is a researcher in the area of sex differences in exercise response, and has looked at the influences of menstrual cycle and hormonal contraceptive use in female athletes on their performance. In this episode, we discuss the research to date, and what this means practically for athletes and coaches. | |||
| #500 – The Big Unanswered Questions in Nutrition Science | 31 Oct 2023 | 01:19:26 | |
Links:
This brings them into areas such as personalized nutrition, ultra-processed foods, time-restricted eating, salt & health, and the difference between being "evidence-based" and "reference-based". We Discuss:
| |||
| #499: How Sensory Cues Impact Food Choice & Behavior – Prof. Ciarán Forde | 24 Oct 2023 | 01:02:05 | |
Links: About This Episode: Sensory cues, comprising taste, smell, texture, and appearance, serve as the initial drivers that influence our food preferences and liking for particular items. These sensory cues can be both inherent, such as the natural sweetness of fruit, and learned, as in the association between a particular aroma and a favorite dish. One crucial aspect of this research is delving into how sensory properties of food, like texture and taste, contribute to our choices and consumption patterns. Food texture, for example, plays a key role in determining how quickly we consume a meal, with softer textures often being associated with faster eating rates. Sensory intensity and palatability are also central themes in this research. Moreover, research into dietary fat reveals intriguing phenomena like "fat blindness," where the ability to discriminate different levels of fat diminishes as taste intensity increases. Understanding these relationships can help shed light on factors contributing to overeating and potential avenues for behavior modification. To give us a better insight into this field of research, Professor in Sensory Science and Eating Behavior at Wageningen University, Prof. Ciarán Forde, is on the podcast to discuss these ideas. | |||
| The PREDIMED Trial – Controversy, Criticisms, & Lessons Learned (SNP 22) | 17 Oct 2023 | 00:17:36 | |
Links: About This Episode: PREDIMED (Prevención con Dieta Mediterránea) is a landmark clinical trial conducted in Spain. The study made a huge splash due to the rarity in nutrition of having large RCTs with hard endpoints. In addition, it had results of a large magnitude; showing a 30% reduction in cardiovascular events. But the study did face criticisms and controversies over methodological issues, including randomization procedures at certain centers, ultimately leading to a retraction of the original paper and a re-analysis. Participants in the PREDIMED trial were randomly assigned to one of three groups:
Despite the issues it still ends up being an incredibly useful source of data. In this episode we discuss the findings from PREDIMED, some of the potential limitations, and where it sits among the wider Mediterranean Diet literature. Note: This is a Premium-exclusive episode, so in order to listen to the full episode you'll need to subscribe to Sigma Nutrition Premium. | |||
| #498: The PROPEL Trial & Weight Loss Interventions in Primary Care – John Apolzan, PhD | 10 Oct 2023 | 00:35:39 | |
Links:
About this Episode: The PROPEL (Promoting Successful Weight Loss in Primary Care in Louisiana) trial was a cluster-randomized weight loss trial, specifically tailored to address the pressing health concerns of an underserved population in Louisiana, where obesity rates have reached alarming levels. The core of the intervention comprises a pragmatic, high-intensity lifestyle-based obesity treatment program, thoughtfully designed to be integrated within primary care settings. Over a 24-month duration, this multi-component weight loss program is delivered by skilled health coaches who are embedded in primary care clinics, with the aim of instigating substantial and sustainable weight loss outcomes. In this study, 803 participants were enrolled, of whom 67% identified as Black and 84% as female, thereby ensuring a diverse representation. The research design randomized 18 clinics, allocating them equally into two groups: usual care and an Intensive Lifestyle Intervention (ILI). The usual care group continued to receive their customary primary care, serving as the benchmark against which the ILI's efficacy will be measured. In this episode we have the opportunity to delve deeper into the intricacies of the PROPEL trial and gain insights from one of its lead researchers, Dr. John Apolzan of the Pennington Biomedical Research Center.
| |||
| #497: Are Food Frequency Questionnaires Reliable? | 03 Oct 2023 | 01:08:14 | |
Links:
About This Episode: Food frequency questionnaires (FFQs) have been widely employed in nutrition research to assess dietary intake patterns among study participants. However, debates surrounding the reliability of FFQs have persisted both inside and outside the academic community. These debates primarily revolve around issues related to measurement error, recall bias, and the appropriateness of FFQs for diverse populations. One prominent concern is the potential for measurement error in FFQs. These questionnaires rely on self-reported data from participants, which can introduce inaccuracies due to memory limitations and social desirability bias. Participants may not accurately recall their food consumption frequencies and portion sizes, leading to imprecise estimates of nutrient intake. Recall bias is another critical issue in the reliability debate. Participants may selectively remember or misreport the consumption of certain foods or nutrients, leading to an overestimation or underestimation of actual dietary intake. Two concepts are crucial to understand: validity and reproducibility. FFQs are validated by cross-referencing the FFQ data with other dietary assessment tools (or other methods). It's also important to consider if an FFQ gives reproducible results when used on multiple occasions. When we ask "are FFQs reliable?", we must first understand the conceptual exposure of interest: average intake over time. Second, we must consider what nutrients we are looking at. And third, in what population. In this episode, Danny & Alan discuss the reliability of FFQs and how to have a deeper, more accurate understanding of their use. They take a look at valid critcisms of FFQs, as well as some of the more ill-informed criticisms. | |||
| SNP21: Sick Individuals and Sick Populations | 26 Sep 2023 | 00:17:48 | |
Links: About this episode: In 1985 a paper titled "Sick Individuals and Sick Populations" was published in the International Journal of Epidemiology. The paper, authored by eminent epidemiologist Geoffrey Rose, can be considered as seminal and important because it brilliantly raised the concept of the "prevention paradox" and challenged traditional approaches to public health and preventive medicine. The paper's insights have had a lasting impact on how we understand and approach population health interventions. And it raised many contentious public health issues, which are still debated and relevant today. The ideas have very important implications for how we can tackle diet-related diseases in meaningful ways. In this episode, Danny and Alan discuss the central themes of the paper, why they are so crucial to understand, and what this means for our understanding of diet and chronic disease prevention. | |||
| #574: Microplastics & Health: What Do We Know? – Prof. Ian Mudway | 26 Aug 2025 | 00:50:53 | |
They're in our oceans, our air, our food, and now even in our bodies. Microplastics, once a distant environmental issue, have become a topic of urgent relevance in medicine, public health, and nutrition. The idea that tiny plastic particles are circulating through the food chain and accumulating in human tissues has sparked headlines, speculation, and concern. But how much of this fear is grounded in solid science? And how much is still unknown? As the research into microplastics rapidly grows, so too does the confusion. Claims range from the plausible to the alarmist, yet the real picture is far more complex. What does current evidence actually tell us about the health implications of microplastic exposure? How do we weigh these emerging signals against the backdrop of other environmental threats we understand much better? And how should scientifically-minded practitioners think about this issue, especially when patients begin asking questions? This is a conversation that calls for clarity, nuance, and a rigorous look at what we know versus what remains speculative. In this episode, Professor Ian Mudway, an environmental toxicologist, discusses the current scientific understanding of microplastics and human health. Timestamps
| |||
| #496: ATBC Cancer Prevention Study – Crucial Lessons | 19 Sep 2023 | 01:01:14 | |
Links:
About This Episode: The Alpha-Tocopherol, Beta-Carotene Cancer Prevention Study (ATBC) stands as a seminal and pioneering research endeavor within the domain of epidemiology and cancer prevention. Conducted in Finland, the study aimed to examine the potential protective effects of alpha-tocopherol (vitamin E) and beta-carotene supplementation against the occurrence of various cancer types, particularly lung cancer, among male smokers. Initiated in the early 1980s, the study's comprehensive design, rigorous methodology, and its focus on a specific high-risk population have contributed significantly to the understanding of the interplay between dietary antioxidants and cancer risk. The ATBC study was founded on a growing body of evidence suggesting the potential role of antioxidants in mitigating the deleterious effects of oxidative stress and free radical damage, which are recognized as contributors to carcinogenesis. The selection of male smokers as the study cohort was strategically significant, given the heightened susceptibility of this group to lung cancer and other malignancies due to the synergistic action of smoking and oxidative stress. The study's rigorous double-blind, placebo-controlled design ensured a high degree of scientific rigor, minimizing biases and confounding factors that might influence the outcomes. One of the primary reasons for the study's seminal status is its contribution to the understanding of the complex relationship between antioxidants and cancer risk. While the study did not find a significant reduction in lung cancer incidence among the intervention group receiving alpha-tocopherol and beta-carotene supplements, its findings spurred critical discussions within the scientific community. The neutral or inconclusive results underscored the intricate nature of carcinogenesis and highlighted the limitations of simplistic cause-and-effect interpretations in the context of cancer prevention. Moreover, the ATBC study contributed to a shift in research paradigms, prompting scientists to explore broader dietary and lifestyle factors that influence cancer risk beyond single-nutrient interventions. In this episode we discuss the three most important publications from the study, with a specific look at what crucial lessons they teach us about the nuances, challenges, and unique aspects of nutrition as a scientific field. | |||
| #495: Circadian Clocks in Muscle & Exercise as a Time Cue – Prof. Karyn Esser | 12 Sep 2023 | 00:35:27 | |
Links:
About this Episode: The field of circadian biology has long been associated with regulating diurnal physiological processes, notably the sleep-wake cycle. However, recent advances have unveiled a broader role for circadian clocks across various tissues, including skeletal muscle. Within this context, the investigation of circadian clocks within the skeletal muscle milieu has emerged as a frontier of scientific inquiry. These intrinsic timekeeping mechanisms exhibit multifaceted regulatory capacities beyond mere temporal synchronization. This episode delves into the implications of "circadian clocks" operating within skeletal muscle tissue, with the esteemed Prof. Karyn Esser as this week's guest. Her pioneering work has been instrumental in understanding the interplay between circadian rhythmicity and muscular physiology. | |||
| #494: Multiple Risk Factor Intervention Trial | 05 Sep 2023 | 00:54:33 | |
Links:
About This Episode: The Multiple Risk Factor Intervention Trial (MRFIT) was a groundbreaking clinical trial conducted in the 1970s and 1980s. Its main objective was to investigate the relationship between various risk factors and the incidence of heart disease. The study aimed to determine whether modifying risk factors, such as high blood pressure, high cholesterol levels, and smoking, could lead to a reduction in cardiovascular events. The trial spanned several years, with participants being followed up for a period of approximately six years to assess the incidence of cardiovascular events and mortality. The primary outcome measures included coronary heart disease (CHD) mortality and overall mortality. The MRFIT trial yielded several important findings that have significantly influenced our understanding of cardiovascular health and prevention strategies. In this episode we take a look at why this is such seminal research, as well as the contribution of one of the greatest researchers ever in the field, Jeramiah Stamler. | |||
| #493: The Keys Equation – How Dietary Fats Impact Blood Cholesterol | 29 Aug 2023 | 00:58:50 | |
Links:
About this Episode: One of the most important and influential papers in nutrition science is one by Ancel Keys and his colleagues that was published in The Lancet in 1957. This seminal paper examined the relationship between dietary fat intake and serum cholesterol levels. The researchers investigated how different types of fats in the diet affected cholesterol levels in a series of their previous tightly-controlled dietary experiments.. Those studies involved feeding the participants various diets with different compositions of fats. The researchers analyzed the participants' blood samples to measure changes in serum cholesterol levels in response to dietary changes. The most important aspect of this paper is the presentation of the 'Keys Equation'; a predictive equation for the impacts of saturated, monounsaturated, and polyunsaturated fats, and dietary cholesterol, on blood cholesterol levels. Crucially, the Keys Equation identifies the importance of the ratio of polyunsaturated to saturated fats in the diet; known as the 'P:S ratio'. It showed that the P:S ratio is the most important dietary factor impacting blood cholesterol levels. And specifically that saturated fats increase total and LDL cholesterol twice as much as polyunsaturated fats lower them. The findings of this study were significant in highlighting the potential impact of dietary fat subtypes on serum cholesterol levels and heart disease risk. It contributed to the growing body of evidence supporting the hypothesis that high serum cholesterol levels, particularly due to a diet rich in saturated fats, were associated with an increased risk of cardiovascular diseases. In this episode, as part of our new series taking an in-depth look at seminal nutrition studies, we go through this influential paper from Keys, Anderson and Grande. | |||
| SNP20: The Cumulative Exposure Model of LDL-C & Heart Disease | 22 Aug 2023 | 00:13:24 | |
This is a Premium-exclusive episode, so here you'll only hear a preview. In order to listen to the full episode you'll need to subscribe to Sigma Nutrition Premium. About This Episode: It has been clearly demonstrated that elevated LDL-cholesterol (LDL-C), or perhaps more specifically pro-atherogenic lipoproteins, is causal in atherosclerosis development in humans. One crucial concept within this is that the risk relates not only to the magnitude of elevated LDL-C, but the duration of exposure. Thus, the role of LDL-C in driving atherosclerosis is referred to as a "cumulative, integrated exposure over the lifecourse". But, what exactly does this mean? In this episode, Danny discusses the cumulative exposure model of LDL-C in atherosclerosis, the evidence supporting it, and the implications of this for the "debates" that get raised in relation to LDL-C (or apoB-containing lipoproteins) and heart disease. Links: | |||
| #492: How Does Weight Cycling Impact Long-term Health? | 15 Aug 2023 | 01:06:19 | |
Links: About This Episode: Losing at least 5% of one's initial body weight is associated with improvements in glycaemic control, blood pressure, triglyceride levels, and other positive outcomes. Due to these reasons, it is typically recommended that individuals classified as overweight or obese should engage in effective weight loss interventions. However, despite the potential for clinically significant weight loss through these interventions, weight regain is a common occurrence. This can be attributed to a combination of low adherence to weight control strategies and compensatory physiological mechanisms that influence weight regain. Consequently, this may result in a cycle of losing and regaining weight over the long term, which is commonly referred to as "weight cycling." There are concerns regarding the potential harm to health and increased risk of chronic diseases associated with weight cycling. Some mechanisms have been proposed, such as the loss of lean mass during weight loss periods that is not regained when weight is regained. However, the evidence supporting the harmful effects of weight cycling on health is incomplete and many unanswered questions remain. In this episode, we will examine the evidence published to date and draw evidence-based conclusions regarding the impact of weight cycling on long-term health. | |||
| #491: Do High Protein Intakes Cause Insulin Resistance? | 08 Aug 2023 | 01:02:53 | |
Links: About This Episode: There has been interest in, and debate about, how protein intake impacts metabolic health, particularly in relation to insulin resistance and type 2 diabetes risk. Recently, there has been interest in higher protein intakes as an intervention in diabetes, owing to a variety of potential mechanisms. For example, the satiety value of protein, the promotion of insulin secretion by protein, and imapcts on incretin hormones. However, others have warned against high protein intakes. With some going as far as to claim high, or even moderate, protein intakes can lead to insulin resistance or negatively effect beta-cell function. In this episode, we look at the research typically cited in support of such claims, and dig into the details. We consider the overall evidence in this area to answer the question 'do high protein diets cause insulin resistance or increase diabetes risk?'. | |||
| #490: How Does Exercise Impact Beta-cell Function in Type 2 Diabetes? – Mark Lyngbæk, MD | 01 Aug 2023 | 00:58:00 | |
Links: About This Episode: The management of type 2 diabetes has long been a challenge, but a new study conducted by researcher Mark Lyngbaek and his colleagues has the potential to add important considerations to the approach to treatment. Titled the "DOSE-EX" randomized clinical trial, their study uncovers the impact of exercise and weight loss on beta-cell function, a key factor in diabetes progression.DOSE-EX is a four-armed randomized trial involving 82 individuals with newly diagnosed type 2 diabetes. The participants were divided into four groups: standard care, calorie restriction, calorie restriction with exercise three times per week, and calorie restriction with exercise six times per week. Over a span of 16 weeks, the researchers assessed the effects of these interventions on beta-cell function using various indicators. The study's findings are incredibly interesting, demonstrating that exercise in combination with diet-induced weight loss leads to a substantial improvement in glucose-stimulated beta-cell function. Importantly, the results indicate the importance of considering both: a) the exercise dose, and b) the methodology of assessing beta-cell function, when evaluating intervention effectiveness. In this episode, Dr. Lyngbaek will elucidate the implications of these findings for the management of type 2 diabetes. We will explore the potential of exercise as a therapeutic tool, its optimal dosage, and the considerations for integrating it into individualized treatment plans. About The Guest: Dr. Mark Lyngbæk is a physician, currently in an introduction position at the Department of Rheumatology and Internal Medicine 2 at Holbæk Hospital, and also a PhD student at the Centre for Physical Activity Research at Rigshospitalet. His research has looked at exercise, beta-cell function and type 2 diabetes. He is supported by a research grant from the Danish Diabetes Academy, which is funded by the Novo Nordisk Foundation (grant number NNF17SA0031406). The Centre for Physical Activity Research is supported by TrygFonden (grants ID 101390, ID 20045, and ID 125132). | |||
| What is a Causal Risk Factor? (AMA with Alan) | 25 Jul 2023 | 00:31:39 | |
Links: About this Episode: We've just released a lengthy 'ask me anything' episode, where Dr. Alan Flanagan addressed specific listener questions, over on the Sigma Nutition Premium feed. In this episode, you'll hear one detailed answer from that AMA, in which Alan discusses the concept of "causal risk factors". This is a term that is regularly mentioned on the podcast, and has a very specific and important meaning. This episode will give you an in-depth understanding and comfort with the term, which will enhance your future understanding and learning. If you wish to hear the other 10 questions Alan answered, you can subscribe to Sigma Nutrition Premium here. | |||
| #489: Inequalities in Diabetes Outcomes for African & Caribbean Communities – Prof. Louise Goff | 18 Jul 2023 | 00:51:16 | |
Links:
About This Episode: In the UK, there is a threefold higher incidence of type 2 diabetes in UK African and Caribbean (AfC) communities, compared to the general population. And ethnic inequalities in type 2 diabetes treatment and outcomes have been documented. And so addressing these inequalities is an urgent healthcare priority in the UK. Differences in outcomes relate to physiological differences as well as pragmatic issues and structural barriers. Professor Louise Goff has done pioneering work in relation to both aspects. Prof. Goff's research has highlighted ethnic differences in type 2 diabetes pathophysiology between those in UK African and Caribbean groups and white Europeans. This means that typical screening for diabetes may not be as useful for AfC communities, in addition to treatments not being as appropriate. In addition, there are noted differences in engagement with diabetes education services and self-management advice. This may be due to the fact that the delivery of information is not culturally relevant to those in AfC communities. And so diabetes structured education programs have been found to be less successful in people from minority ethnic groups. Prof. Goff has attempted to address this by developing a culturally tailored self-management education and support program for type 2 diabetes in black-British adults. This program, called the Healthy Eating and Active Lifestyles for Diabetes (HEAL-D) program, has initially been trialed with local Black African and Caribbean communities and healthcare providers in South London. In this episode, Prof. Goff discusses the ethnic differences in diabetes pathophysiology and the other factors underlying the inequalities in diabetes outcomes in black African and Caribbean communities. | |||
| #573: A Philosophy of Elite Performance Nutrition – Daniel Davey | 12 Aug 2025 | 00:55:03 | |
In this episode, performance nutritionist Daniel Davey discusses how his approach to elite sports nutrition has evolved over his career. Davey reflects on his decade working with top Irish teams (Dublin GAA/football and Leinster Rugby) and how stepping away from those environments led him to rethink the role of a nutrition practitioner. The central theme is a shift from a traditional prescriptive model, where the expert provides meal plans and quick solutions, to a philosophy centered on athlete empowerment, education, and long-term habit development. Davey emphasizes that true high performance is achieved not by spoon-feeding athletes every nutrient, but by cultivating their independence, adaptability, and ownership of the process. This episode delves into practical strategies for fostering that ownership, such as encouraging self-reflection, building a supportive "nutrition culture," and focusing on sustainable habits over short-term fixes. This discussion is highly relevant to nutrition science and clinical practice because it addresses the often-overlooked behavioral and cultural aspects of dietary change. Health professionals will recognize parallels to coaching clients in any setting: the importance of engaging individuals in their own nutrition planning, the value of reflective practice, and the balance between providing support and encouraging autonomy. Timestamps
| |||
| #488: Does Time of Day Impact Hunger, Appetite & Satiety? | 11 Jul 2023 | 01:27:47 | |
Links: About This Episode: The topic of whether hunger and satiety are affected by the time of day has generated considerable interest within the nutrition research community. Researchers have been particularly intrigued by the potential influence of circadian rhythms on caloric intake throughout the day. Initially, a number of studies proposed that consuming high energy intakes in the morning could lead to significantly greater weight loss compared to evening consumption. And while much attention was placed on the hypothesis that differences in expenditure were the cause, more recent research has called that into doubt. And so, it is crucial to consider the possibility that other factors may be contributing to the outcomes observed in the intervention trials. In recent years, a series of papers has suggested an alternative explanation; the impact of time-of-day energy intake on appetite and hunger. In this episode, Alan and Danny take a look at the current evidence related to this connection between time-of-day, appetite, and energy intake. And then, from that, what does this mean for how calorie distribution may affect dietary intake, body composition and health. | |||
| #487: Weight Cutting in Combat Sports – Jordan Sullivan | 05 Jul 2023 | 01:15:00 | |
Links:
About This Episode: "Weight cutting" is a common practice in weight-class based sports. And typically, combat sport athletes have reported cutting the largest amounts of weight for competition. The concept of cutting weight is based on the assumption that a size advantage gives a performance advantage in combat sports. And by getting into a lower weight class than their "normal" weight, athletes can enjoy an advantage (or, more accurately, not be at a disadvantage). The decrease in weight from an athlete's habitual weight to their weight-class limit typically has two phases: a chronic weight loss phase (gradual dieting to lose fat mass), and an acute weight loss phase (rapid declines in weight due to losses of water, glycogen and gut residue). To discuss the science, practical application and dangers of weight cutting strategies, performance dietitian Jordan Sullivan is on the podcast. Jordan has been the performance dietitian for several years to Israel Adesanya, Alexander Volkanovski, Leon Edwards, Dan Hooker, Kai Kara-France, and many other well-known names. And he is the co-author, along with Danny, of the new textbook 'Making Weight: The Ultimate Science Based Guide to Cutting Weight for Combat Sports'. | |||
| #486: Blood Glucose Spikes: How High is Too High? – Mario Kratz, PhD & Nicola Guess, PhD | 27 Jun 2023 | 01:21:05 | |
Links:
About This Episode: Peaks in blood glucose (or "blood sugar spikes") are commonly highlighted as something harmful to health. And, of course, an excessively high blood glucose response to a meal can be problematic, or at least indicate there is a problem. However, elevations in blood glucose after eating are a normal physiological response. And "bad" blood glucose responses are those that stay high for a prolonged period; i.e. after elevating, they don't return to normal within an appropriate period of time. But now many normoglycemic people are worrying about normal blood glucose responses, due to information that portrays even moderate elevations in blood glucose as harfmul. To add to the confusion, people are looking at standardized cut-off thresholds for diabetes and pre-diabetes, and mistakenly using them to label their own response to eating as measured by a continuous glucose monitoring (CGM) device. When it comes to normoglycemic people, there is still a grey area in relation to how much of a glucose spike is a cause for concern. And given that there are still open questions that evidence has not fully answered yet, there is room for different interpretations of how to answer this question. So what actually is a blood glucose peak that is "too high"? Is it 7.8 mmol/L (140 mg/dL)? 10.0 mmol/L (180 mg/dL)? 11.1 mmol/L (200 mg/dL)? Or do we even need to think about this once standard measures (e.g. HbA1C) are normal? To discuss this interesting area, Dr. Mario Kratz and Dr. Nicola Guess are on the podcast to offer some perspectives and their conclusions from the current evidence base. Blood Glucose Unit Conversions:
| |||
| #485: Does Menopause Alter Appetite? | 20 Jun 2023 | 00:45:14 | |
Links: About This Episode: Menopause is commonly associated with hormonal changes and physical symptoms, such as hot flashes, mood changes, sleep issues, and weight gain. Based on anecdotal reports, another interesting question emerges: what is the potential impact of menopause on appetite? As women undergo this transformative phase, many report fluctuations in their food intake and body weight, raising the question: Does menopause alter appetite? Understanding the relationship between menopause and appetite is of great significance, as it can potentially provide insights into the mechanisms behind weight gain and obesity risk that often accompany this stage of life. Furthermore, comprehending the factors that contribute to changes in appetite during menopause could aid in the development of tailored interventions and strategies to support women's overall health and well-being. In this episode, we delve into the research to see if we can unearth any answers. What studies have been done? What results do we see? What conclusions does this allow us to make? And what does future research need to do in order to provide better answers? | |||
| SNP18: What is a Healthy Low-Carb Diet? | 13 Jun 2023 | 00:13:38 | |
Links:
About This Episode: Note: This is a Premium-exclusive episode, so in order to listen to the full episode you'll need to subscribe to Sigma Nutrition Premium. Low-carbohydrate diets come with a list of reported benefits, and research does show benefit for a number of different outcomes. However, many influencers and advocates of low-carb diets routinely add commentary that is misleading, incorrect, and possibly dangerous. This has led to us highlighting such incorrect information on this podcast before and pushing back against central claims of the "big names" in the "low-carb community". However, low-carbohydrate diets can indeed be a viable dietary pattern for people who wish to consume a healthy diet… provided they meet a few criteria. In other words, it is possible to consume a low-carb diet that still largely fits in with the evidence we have on healthy dietary patterns. In this episode, Danny discusses what health outcomes may result from low-carb diets, and what distinguishes a "healthy low-carb diet" from an "unhealthy low-carb diet". This includes some pragmatic tips for nutritionists, health professionals and consumers, who are choosing to use a low-carbohydrate diet. | |||
| #484: Is Metabolic Adaptation an Illusion? – Eric Trexler, PhD | 06 Jun 2023 | 01:15:37 | |
Links: About This Episode: Metabolic adaptation refers to the process by which the body adjusts its metabolism in response to changes in energy intake or body mass. This adjustment can occur in both directions, meaning that the body can increase or decrease its energy expenditure in response to changes in energy intake or body weight. When someone consumes fewer calories than their body requires for energy, the body will respond by slowing down its metabolism to conserve energy. This can make it harder to lose weight and maintain weight loss over time. Conversely, when someone consumes more calories than their body needs, the body will increase its metabolic rate in order to burn off the excess energy. There are several open debates in science about metabolic adaptation, including the actual magnitude of it, its relevance to weight loss, what measurement methods should be used, and the mechanisms underlying the contributory factors. Some people have framed metabolic adaptation as so significant that it makes weight loss attempts futile. While others, including in research, have referred to metabolic adaptation as an "illusion". So what do we actually know about this concept and what is the pragmatic significance of it? To discuss the nuances of the topic, Alan and Danny are joined by Dr. Eric Trexler, who has published on this topic and has followed recent publications closely. About The Guest: Dr. Eric Trexler is Director of Education at Stronger By Science, where he co-hosts the SBS podcast. He also is one of the four contributors to the MASS Research Review. Eric has a prolific background in exercise science research, with more than 30 publications to his name by the time he completed his PhD at UNC-Chapel Hill. --- | |||
| #483: What are the Effects of Very High Fiber Intakes? | 30 May 2023 | 01:18:00 | |
Links:
About This Episode: The benefits of consuming a higher fiber diet have been consistently demonstrated in nutrition research. Epidemiology clearly shows that higher intakes, compared to lower intakes, leads to a risk reduction for a range of diseases, including cardiovascular disease and colon cancer. And based on this epidemiological evidence, most dietary guidelines recommend dietary patterns that provide adults with 30-35g of dietary fiber per day. However, what do we know about intakes beyond this? Do we continue to see benefit in a linear fashion? Is there a ceiling to benefit? At what level would we see "optimal" benefit or the greatest magnitude of risk reduction? The ability to answer such questions is hampered by the fact it's difficult to find cohort studies where the "high" fiber level is high enough to relate to this issue. However, there have been some controlled studies looking specifically at "very high" intakes, i.e. those far above current recommendations. In addition, there are some populations where habitual dietary intake gives a fiber intake far above the typcial intakes in Western cohorts. So in this episode we go through this data to try to see what we can conclude about this fascinating question of 'what are the health effects at very high fiber intakes?' New to Sigma Nutrition? Learn more about us here. | |||
| #482: Carbohydrate Quality & Health – Andrew Reynolds, PhD | 23 May 2023 | 01:06:49 | |
Links: About This Episode: In the last couple of decades, carbohydrates have experienced an increasing amount of negative campaigning. In general, the main argument is that carbohydrates have been viewed as the root cause for obesity, diabetes and several other diseases including heart disease and behavioral disorders. However, there can often be a lack of appreciation that not all carbohydrates are equal in their health effects. Beyond this, now there has even been confusion as to whether high fiber diets with whole grains are good for you or bad. This is mostly a result of strong claims made by people with large online followings and promoting specific diets. What does the best evidence tell us about different carbohydrate types and impacts on health outcomes? Should carbohydrates be viewed as inherently harmful? How solid is the evidence on whole grains, legumes and other high-fiber carbohydrate-rich foods? To help us tease through the science in this area, in this episode we get some answers from nutrition epidemiologist, Dr. Andrew Reynolds. About the Guest: Dr. Andrew Reynolds is a nutrition epidemiologist working with achievable lifestyle and environment change in the prevention and management of non-communicable diseases, such as type 2 diabetes and cardiovascular disease. He primarily conducts randomised controlled trials and meta-analyses. Much of his work is to inform evidence-based dietary or clinical guidelines, policy, and food reformulation. Links: | |||
| Is Personalized Nutrition Superior to General Nutrition Advice? (SNP 17) | 16 May 2023 | 00:22:57 | |
Links: About This Episode: "Personalized nutrition" has been promoted as an approach that will improve people's health by prescribing them specific dietary recommendations based on their own genetic and phenotypic data. The premise is that given we each respond differently to foods, having general dietary recommendations may be doing many people a disservice. And by using an array of personal data, it is now possible to give unique diets that improve health. The early and interesting findings of research in this area was met with much fanfare, and indeed, many companies are now offering commercial direct-to-consumer services based on genetic and physiological testing, followed by "personalized" dietary prescription. Such testing may include genetic tests, microbiome testing, glucose monitoring data, and more. This data is then fed into machine learning algorithms to prescribe dietary recommendations. However, do the marketing claims match the current evidence? Does the "proof" it works that is often cited, actually back up the claims? Do personalized nutrition diets actually lead to improved health outcomes over generic, conventional dietary recommendations? Do personalized nutrition diets lead to better outcomes than standard dietetic/nutrition practice? To answer these questions, we go through the main studies cited in favor of personalized nutrition being superior to typical dietary advice, and see if they indeed support the claims. So is personalized nutrition superior to standard dietary advice? Let's find out… Note: This is a Premium-exclusive episode, so in order to listen to the full episode you'll need to subscribe to Sigma Nutrition Premium. However, you can listen to a preview here. | |||
| #481: Why Saturated Fat Really Does Impact Heart Disease Risk | 09 May 2023 | 01:30:10 | |
Links:
About This Episode: While it has long been acknowledged that high intakes of saturated fat can increase risk of atherosclerotic cardiovascular disease due to their impact on blood lipids, there are some who question the association between saturated fat and heart disease. Specifically, they may state that the evidence for this association is weak or non-existent, typically by pointing to some commonly cited studies that show null associations between saturated fat and CVD outcomes. On this basis, they may conclude that there is no basis to aim to limit saturated fat intake to current recommended levels or that reducing saturated fat intake will not actually improve health outcomes. In this episode, Alan and Danny look at the four most commonly cited publications showing a null association, highlighting some key issues. Beyond that, they look at a number of other lines of evidence on saturated fat that allows one to come to a confident answer on this question. So does reducing saturated fat intake to recommended levels actually reduce heart disease risk? Let's discuss… | |||
| #572: Can You Trust Industry-Funded Nutrition Studies? Here's How to Tell | 05 Aug 2025 | 01:09:40 | |
Nutrition science plays a pivotal role in shaping public health advice, but the influence of industry funding on research has become a pressing concern. In this episode we want to examine whether we can trust nutrition studies funded by food and beverage companies, and how you can discern study credibility. The discussion is highly relevant in today's landscape, where conflicts of interest and bias in research are under scrutiny amidst debates on sugar, processed foods, and diet recommendations. By exploring how industry sponsorship might skew results or interpretations, this episode speaks to broader issues of scientific trustworthiness and evidence-based policy in nutrition and public health. In this episode, we take a look at some recent publications that showed how study results and reporting differed significantly depending on if industry had funded the study or not. We delve into how this happens. As most often it is not a case of data fabrication or corruption, but rather how bias leads to studies being designed and reported differently. We walk through some examples, as well as highlighting some industry-funded studies that didn't provide a "pro-industry" result and conclusion. The hope is that the episode allows you to understand why this is a problem, how to spot it, and how to know if you can trust the results of an industry-funded study. Timestamps
| |||
| #480: How Much Fiber Do We Need for Good Health? – Prof. Joanne Slavin | 02 May 2023 | 01:10:12 | |
Links:
About this Episode: The beneficial impact of a high-fiber diet is something that has been promoted in nutrition for a long period of time. But there remain a variety of interesting questions to researchers, practitioners and the general public alike. How much fiber do we actually need? What are current fiber recommendations based on? What outcomes have the strongest evidence for benefit? Should we have targets for fiber sub-types? Are some types of fiber "better" than others? Do functional fibers added to food products still retain the benefits we see with dietary fiber? To help get to some evidence-based answers on these issues, our guest in this episode is one of the researchers at the forefront of dietary fiber research for decades, Professor Joanne Slavin. | |||
| #479: Blood Glucose, CGM Use, Diabetes Remission & High-Protein for Diabetes – Nicola Guess, PhD, RD | 25 Apr 2023 | 00:50:41 | |
Links: Description: Blood glucose responses play a crucial role in maintaining good health, and any abnormalities in glucose regulation can lead to several chronic conditions. Diabetes is one such disease that results from a lack of insulin production or the body's inability to use insulin effectively, leading to elevated blood glucose levels. There has been debate about what exactly constitues a "healthy" and "unhealthy" blood glucose response. While it is suggested that unhealthy blood glucose responses are characterized by erratic and unpredictable "spikes" in blood glucose levels, sometimes vague terminology leads to people worrying about normal blood glucose responses. This may be particularly related to the increasing prevalence of continuous glucose monitoring (CGM) devices that allow individuals to track their glucose levels in real-time. While these devices can be helpful for people with diabetes to manage their glucose levels, they can also lead to unnecessary concern and anxiety about small, normal glucose elevations. In recent years exciting advances have been made in diabetes remission research. And off the back of that, more research has looked at various dietary interventions that could either directly impact remission, or act as an adjuct to other interventions. In this discussion with Dr. Nicola Guess, we discuss a range of topics related to glycemia, diabetes, and diet. This includes the potential for high-protein interventions, what utility CGMs actually have, what to make of diabetes remission trials, and future directions for the field. | |||
| #478: Exposures in Nutrition – Why They're Crucial to Understand | 18 Apr 2023 | 01:02:23 | |
Links:
Description: Understanding the concept of an "exposure" is a critical aspect to nutrition science literacy. The 'exposure of interest' refers to the variable or factor that is being studied to determine its relationship with a particular health outcome. For example, in a study examining the relationship between diet and heart disease, the exposure of interest may be a particular nutrient or food group, such as saturated fat or red meat consumption. But when reading research we need to be able to critically examine the levels of an exposure and ask were these suitable for the research question at hand. For example, is there a sufficiently wide contrast in the exposure between the groups being compared? How do the reported levels of intake relate to what we know about this exposure from the wider literature? Much has been made of the many 'null' associations found in nutrition epidemiology. But in many cases, these may be accounted for by looking at the exposure contrast or absolute intakes in those studies. Something we referred to as "null by design". In this episode, Danny and Alan go through the most crucial aspects to understand about the exposure of interest in nutrition, hopefully leading to an enhanced understanding of interpreting nutrition research.
| |||
| SNP16: A Dairy Fat Paradox? – Saturated Fat, Food Matrices & Heart Disease | 11 Apr 2023 | 00:22:11 | |
Links:
Description: Substantial evidence shows that a high intake of saturated fat in the diet has the potential to significantly raise LDL-C and ApoB-containing lipoproteins in many people, and in turn increase their risk of developing atherosclerotic cardiovascular disease (ASCVD). However, people may raise what seems to some contradictory evidence, or what is sometimes thought of as a paradox: the impact of full-fat dairy on CVD risk. This paradox arises because given the saturated fat content of full-fat milk, yogurt and cheese, we typically don't see the same impact on blood lipid profiles. In addition, epidemiology can often show such foods in a favourable light. And the dairy fat story gets more interesting when we look at evidence showing there is a huge difference in the impact of consuming different dairy foods (e.g. butter vs cheese/yogurt). So this leads to many questions that people rightly ask, which we aim to address in this episode. Questions such as:
| |||
| #477: Effect of Different Diets on Cholesterol, Lipoproteins and Discordance – Ian Davies, PhD | 04 Apr 2023 | 00:54:24 | |
Links:
Introduction: Discordance between low-density lipoprotein particle (LDL-p) and low-density lipoprotein cholesterol (LDL-C) occurs when the levels of these two biomarkers do not match up as expected. Discordance between Apolipoprotein B (ApoB) and low-density lipoprotein cholesterol (LDL-C) is similar, except rather than counting just LDL particles, ApoB is a measure of the numbers of lipoproteins that have an ApoB attached. Discordance between ApoB and LDL-C can lead to either an underestimate or overestimate of ASCVD risk. And therefore there may be important implications for someone who does have discordance. Additionally, it is such cases that suggest that a measurement of ApoB may provide additional information beyond traditional lipid measures in assessing a person's cardiovascular risk. Recent work from researchers at Liverpool John Moores University has investigated whether discordance is associated with certain dietary patterns. In this episode, one of the researchers involved, Dr. Ian Davies, is on the podcast to discuss this work in addition to wider questions in the diet-lipids-CVD field that remain to be answered. | |||
| #476: Fructose in Perspective – Dietary Villain or Misunderstood Nutrient? | 28 Mar 2023 | 00:52:21 | |
Links: Description: Fructose is a type of sugar that is commonly found in fruits, vegetables, and many processed foods. In recent years, there has been a lot of discussion and debate about the impact of fructose on health, with some claiming that it is a major contributor to obesity, diabetes, and other chronic diseases. However, these claims are often at odds with what the scientific literature actually says. One of the most common claims about fructose is that it is inherently "bad" for health, and that consuming too much of it can lead to a wide range of health problems. This idea has been popularized in many popular diet and health books, and has led to a widespread fear of fructose among the general public. However, many of these claims are based on outdated or oversimplified research, and do not reflect the complex reality of how fructose interacts with the human body. Another common claim about fructose is that it is uniquely responsible for the current obesity epidemic, and that reducing fructose intake is the key to weight loss and better health. While it is true that excessive consumption of sugary foods and beverages can contribute to weight gain and other health problems, the idea that fructose is uniquely responsible for these issues is not supported by the scientific evidence. In fact, many studies have found that total sugar intake, rather than fructose specifically, is the most important factor in the development of obesity and related health problems. In this episode we discuss the unique aspects of fructose metabolism, why some studies appear to show unique harm of fructose, and the implications of this for dietary choices. | |||
| #475: Is Food Addiction Real? – Charlotte Hardman, PhD | 22 Mar 2023 | 00:55:54 | |
Links: Description: The idea of food addiction has gained a lot of attention in recent years, as obesity rates continue to rise around the world. Many people struggle with overeating and find it difficult to resist certain foods, leading to a cycle of guilt and shame. The concept of food addiction suggests that there may be a biological explanation for this behavior, and that certain foods may be especially "rewarding" to the brain, leading to a kind of addiction. To help look at the evidence in this area, our guest in this episode is Dr. Charlotte Hardman, who is a leading researcher in the field of appetite and obesity. Dr. Hardman's research focuses on the psychological and biological processes that contribute to overeating and obesity. She is particularly interested in the concept of "food addiction," which suggests that certain foods may be addictive and lead to compulsive overeating, similar to substance addiction. In this podcast, we will explore the latest research on food addiction with Dr. Hardman. We will delve into the evidence for and against the idea of food addiction, as well as discuss the potential implications for public health and policy. Join us as we explore this fascinating topic and learn more about the complex relationship between food and the brain. | |||
| SNP15: AMA – Semaglutide, "Carni-nutrients", Sweating From Caffeine, & More | 17 Mar 2023 | 00:27:05 | |
Questions Answered in this AMA
This is an episode exclusive to Premium subscribers. To listen to the full episode you'll need to subscribe. However, you can listen to a preview here.
| |||
| #474: Glucose Peaks & Variability – Is Lower Better? | 13 Mar 2023 | 01:22:46 | |
Links:
About This Episode: Often claims are made recommending that people should aim to keep peaks in blood glucose low in terms of both magnitude and frequency. And while many claims about blood glucose "spikes" are incorrect or purposefully exaggerated to grab attention, there are some reasonable and interesting hypotheses put forward in relation to blood glucose variability and excursions. For example, interesting questions have been raised in relation to the impact of blood glucose excursions in seemingly normoglycemic and/or healthy people. In this episode, we look at three specific elements of this: average blood glucose, glucose variability, and glucose peaks. All in the context of people without prediabetes or type diabetes, who have typical blood glucose measures in the 'normal' range. Specifically, we look at three hypothesized recommendations made elsewhere:
Can normoglycemic people benefit from further reducing these measures? Let's take a look… | |||
| #473: Diet & Depression (What Do We Actually Know?) – Nicole Lippman-Barile, PhD | 07 Mar 2023 | 01:12:40 | |
Links: Introduction Depression is a common disorder and is a leading cause of disability worldwide. Depression results from a complex interaction of social, psychological, and biological factors. Diet has been one area that has been suggested in playing a role; from potential for exacerbating symptoms to being a treatment. And while some associations have been noted, many claims far exceed what (little) evidence exists. Online it is common to see people claiming certain diets can treat depression or that certain foods will improve outcomes. However, does the evidence match such claims? In trials that have been published on diet-depression, there has been considerable media attention and fanfare around some results. For example, the SMILES trial published out of Australia. However, some have raised considerable concerns about the interpretation of such findings. In this episode, clinical psychologist Dr. Nicole Lippman-Barile is on the podcast to discuss what we currently know about diet and depression, what issues exist with current studies, and why many nutrition-mental health studies are being incorrently interpreted. | |||
| #571: Is Zone 2 Training Actually Best for Health? – Prof. Brendon Gurd | 29 Jul 2025 | 00:38:27 | |
In recent years "Zone 2 training" has gained immense popularity in fitness and health circles, often being proclaimed the "best" cardiovascular training for metabolic health. Zone 2 training is sustained, low-intensity exercise below the lactate threshold that is commonly employed by many elite level endurance athletes, with a variety of proposed performance benefits. This led to interest from health-conscious folks about its ability to improve markers like VO2 max and mitochondrial function, which are associated with better health outcomes and longevity. Prof. Brendon Gurd, an exercise physiologist at Queen's University, is the co-author of a recent review published in Sports Medicine that examined some of the claims made around zone 2 training and health in the general population. This episode looks at whether the evidence truly supports Zone 2 as a uniquely effective training zone or if this hype has outpaced the research. These insights help professionals and individuals make evidence-based recommendations and avoid unintended negative consequences of following certain ideas. About The Guest Dr. Brendon Gurd is a Professor in the School of Kinesiology and Health Studies at Queen's University, where his research focuses on exercise physiology and skeletal muscle adaptation. His work explores how different intensities and types of exercise influence mitochondrial content and function in muscle tissue, with the goal of understanding how to optimize health and performance through training. Timestamps
| |||
| #472: Compared To What? – Understanding Food Substitution Analysis & Adjustment Models | 28 Feb 2023 | 00:53:19 | |
Links:
Description: When thinking about the effect of eating or not eating a certain food or nutrient, we can't consider this in isolation. Meaning, we need to evaluate the impact within the context of what such an inclusion/exclusion does to an individual's overall diet pattern. Thinking about this concept, the phrase "compared to what?" has been colloquially used. And while this is an important idea, there has been some misapplication of this principle. In nutrition science, this is related to the concept of food or nutrient "substitution". And this concept is crucial to understanding the issues that can arise in nutrition studies, particularly when it comes to single food analyses in nutritional epidemiology. This concept of substitution is quite intuitive in controlled feeding studies. However, it is not as obvious when considering nutrition epidemiology studies. As noted by Ibsen & Dahm (2022): "Whereas studying the effects of eating one food instead of another is typically explicit in interventional study designs, it is often implicit and sometimes hidden in analyses of observational studies." However, in nutrition epidemiology substitution is still happening, but it typically emerges as a consequence of adjustment models. In nutritional epidemiology, it is essential to adjust for confounders. E.g., one vital adjustment is often for total calorie intake. However, when our exposure is a specific food/nutrient, we must think about confounding by other foods. So knowing what, and how, a study is adjusting for variables helps us interpret it better. In this episode, Dr. Alan Flanagan and Danny Lennon discuss these crucial ideas of food substitution, adjustment models, and "compared to what?". | |||
| #471: Salt & Bone Health – Is There Cause For Concern? | 21 Feb 2023 | 00:57:33 | |
Links:
About This Episode: Does sodium lead to calcium losses? Do high-salt diets harm bone health? At what thresholds could there be an impact? Does any of this change our recommendations around salt/sodium intake? Thanks to Sigma Nutrition Premium subscriber Kate Wall for submitting a question in the member's area that inspired this episode. Kate asks: "Salt can impact calcium excretion in the urine and it is said that a high salt diet can increase risk of osteoporosis as it draws calcium from the bone and excretes it. How much of an impact does dietary salt intake actually have on bone health and how high would salt intake have to be for this to be a concern? Obviously high salt intakes are not something to aim for in general, but just wondered if this was a mechanism that could remove meaningful amounts of calcium in a way that I should be advising around this in those that we work with as nutritional professionals. Thanks!" So in this episode, Danny and Alan look at some of the evidence in this area to see if there are impacts that have pragmatic implications for nutrition and medical professionals, as well as health-concious people. | |||
| SNP14: Nutrition Coaching Roundtable (Helms, Huschtscha & Baker) | 14 Feb 2023 | 00:09:42 | |
Links:
Description: Nutritionists, dietitians and other health & fitness professionals face many challenges when attempting to help their clients and in understanding what approaches are best in a given situations. There are often discussions around improving client adherence to dietary recommendations. However, sometimes we need to think deeper about this topic. Is there really just a tool to fix this? Or could the problem be the recommendations themselves? Similarly, while quantifying dietary intake in terms of calorie and macronutrient amounts can be useful in some cases, it's clear that this isn't the best approach in many cases. So for coaches aiming to help athletes or those with body composition goals, how do we use "non-tracking" approaches effectively? This episode brings you a roundtable discusssion between three accomplised and insightful nutrition professionals; Dr. Eric Helms, Dr. Zoya Huschtscha, and Mackenzie Baker. In the episode we discuss the above-mentioned topics and more. | |||