#569: The History of Fat, Cholesterol & Heart Disease

The idea that saturated fat might be harmful to our health has sparked controversy for decades. In recent years, counter-narratives have surged: suggesting that concerns over saturated fat were overblown, that LDL cholesterol doesn’t matter, or that the original diet-heart hypothesis has been debunked. These claims have become especially popular in online wellness spaces and certain dietary communities, often wrapped in compelling but misleading rhetoric. So what does the best available evidence actually say? And how should we think about saturated fat, LDL cholesterol, and cardiovascular risk in the current day? In this wide-ranging interview, originally recorded for the Chasing Clarity podcast, Alan and Danny explore the scientific consensus around saturated fat’s impact on blood lipids, why LDL and apoB are central to atherosclerotic disease, and how dietary patterns can meaningfully reduce risk. Importantly, they also address some of the most persistent myths and half-truths that fuel confusion, from flawed interpretations of the Seven Countries Study to misrepresentations of newer meta-analyses. Timestamps [03:41] How do we know saturated fat impacts LDL-C? [05:28] Metabolic ward studies and key findings [11:13] The Keys equation and subsequent research [17:17] Epidemiology and long-term studies [31:48] The Seven Countries Study [44:25] Understanding the impact of saturated fat on blood lipids [47:23] Historical and research perspectives on saturated fat [50:43] Practical dietary strategies for improving blood lipids [53:48] The Portfolio Diet and other dietary interventions [58:07] The role of pharmacology in managing blood lipids [01:00:58] Addressing misconceptions and common claims [01:13:57] Key ideas segment (premium-only) Related Resources Subscribe to Sigma Nutrition Premium Join the Sigma email newsletter for free Enroll in the next cohort of our Applied Nutrition Literacy course Alan Flanagan’s Alinea Nutrition Education Hub Related episodes to add to your podcast queue: 532, 525, 515, 493, 481, 439  

To what extent can maternal nutrition during pregnancy influence a child’s later cognitive or behavioural development? While genetic and environmental factors are known to contribute to neurodevelopmental outcomes such as ADHD and autism, growing attention is being paid to the potential role of prenatal exposures, including dietary patterns. Yet, evidence in this area remains limited, and causality is difficult to establish. One recent study aimed to explore this question by analysing how maternal diet quality during pregnancy (specifically, adherence to a Western-style dietary pattern) related to neurodevelopmental outcomes in children assessed clinically at age 10. In this episode, Dr. David Horner discusses the findings from this prospective cohort study, the use of metabolic markers to complement dietary data, and the implications for future research into modifiable prenatal risk factors. About The Guest Dr. David Horner is a researcher in maternal nutrition and cardiometabolic health, based at the University of Copenhagen, Denmark. He is also a qualified medical doctor from Queen’s University of Belfast. His research is driven by a keen interest in modifiable determinants of health, aiming to better understand and improve health outcomes. Having worked as a medical doctor for 2 years in the UK, in 2017 Dr. Horner then moved to Copenhagen, where he completed a Master’s in Global Health and a PhD examining the impact of maternal dietary patterns during pregnancy on child health. Timestamps [02:47] Introduction to the study [07:08] Strengths and findings of the study [21:17] Genetic factors and gene-environment interactions [25:42] Metabolomics and potential mechanisms [30:12] Interpreting the study’s findings [38:03] Future research directions [42:50] Key ideas segment (Sigma Nutrition Premium) Related Resources Subscribe to Sigma Nutrition Premium Join the Sigma email newsletter for free Enroll in the next cohort of our Applied Nutrition Literacy course See Sigma's "recommended resources" list Email: [email protected] Study: Horner et al., 2025 – A western dietary pattern during pregnancy is associated with neurodevelopmental disorders in childhood and adolescence David’s LinkedIn post about the study (with discussion in the comments)

For decades, dietary guidelines—and the Food Pyramid in particular—have been at the center of heated debates and considerable controversy. These guidelines have often been accused of being influenced by industry interests, oversimplifying nutritional nuance, or even directly contributing to rising obesity and metabolic disease rates. In this episode, we critically assess common claims surrounding the Food Pyramid, including whether it was truly shaped by vested industry interests, if it encouraged harmful dietary shifts toward excessive carbohydrate and sugar consumption, and whether the subsequent health outcomes seen at the population level can be fairly attributed to these guidelines. Additionally, we evaluate the role of the sugar industry in funding key studies and publications, examining the implications such conflicts of interest may have had on nutritional science. Drawing on historical context, rigorous examination of scientific evidence, and an evaluation of how nutritional recommendations have evolved, this discussion aims to clarify misunderstandings, highlight legitimate criticisms, and separate fact from persistent myths regarding dietary guidance and its implications for health. Timestamps [01:37] Common claims and narratives [03:15] Historical context of dietary guidelines [21:57] Sugar industry influence on dietary research [36:17] The mcgovern report [40:49] Misconceptions about dietary guidelines [44:28] Changes in food supply and consumption [58:15] Critiques and conflicts of interest [01:06:47] Key ideas segment (Premium-only) Links & Resources Go to episode page (with linked resources) Subscribe to Sigma Nutrition Premium Join the Sigma email newsletter for free Do you want to be skilled in reading nutrition studies? Enroll in the next cohort of our Applied Nutrition Literacy course Alan Flanagan’s Alinea Nutrition Education Hub MASS Research Review - latest training and nutrition research relevant to strength trainees Examine is the best online database for looking at the evidence of diets, foods and supplements on a range of health outcomes.

Inflammation has become a nutrition buzzword, often used in extreme or misleading ways. This episode aims to clarify what inflammation is, how it relates to diet and health, and whether specific foods truly provoke inflammatory responses in the body. The episode provides a nuanced, evidence-based look at inflammation and diet. It explains the difference between acute and chronic inflammation, outlines the role of chronic low-grade inflammation in disease, and emphasizes that overall dietary patterns – rather than any single food – are what influence our inflammatory status. Commonly demonized foods (such as sugar, wheat, and dairy) are scrutinized, and the conversation debunks myths about them being uniformly “inflammatory.” In this episode, Danny takes a look at what the scientific evidence actually shows about anti-inflammatory diets. Note: This is a Premium-exclusive episode. Timestamps 01:06 Understanding Inflammation: Basics and Biomarkers 04:02 Acute vs. Chronic Inflammation 14:21 Biomarkers of Inflammation 22:51 Dietary Patterns and Inflammation 34:53 Specific Foods and Nutrients Impacting Inflammation 47:01 Practical Takeaways for an Anti-Inflammatory Diet 51:30 Conclusion Related Resources Subscribe to Sigma Nutrition Premium Enroll in the next cohort of our Applied Nutrition Literacy course Related podcast episodes: 329: Diet & Inflammation 353: James Hébert, ScD – Dietary Inflammatory Index Sigma Statement: Nutrition & Immune Function The Dietary Inflammatory Index (DII) – Hébert et al., 2019

GLP-1 receptor agonists have changed the landscape of obesity treatment, offering levels of weight loss once thought unattainable without surgery. But what happens after the weight is lost? And can we really talk about success without talking about maintenance? While much of the public discourse fixates on dramatic weight loss numbers, the harder question is what comes next. Can lifestyle interventions alone sustain weight loss after GLP-1 cessation? How do metabolic adaptations and behavioral relapse factor in? And what does the data actually show about relapse rates, nutritional adequacy, and lean mass preservation when using these medications? In this episode, Danny sits down with Tara Schmidt, dietitian at the Mayo Clinic, to examine the intersection of pharmacology and behavior in long-term weight management. Tara Schmidt is a registered dietitian and an instructor of nutrition at Mayo Clinic. As the lead dietitian for the Mayo Clinic Diet, she provides guidance rooted in evidence-based principles. She hosts the Mayo Clinic On Nutrition podcast and co-authored The Mayo Clinic Diet: Weight Loss Medications Edition. Timestamps [05:17] Understanding weight loss maintenance [08:44] Defining success in weight loss maintenance [11:54] Predictors of maintenance: self-monitoring and behavioral strategies [23:37] Pharmacological interventions: GLP-1 receptor agonists [31:06] Dietary considerations for those taking GLP-1 RAs [37:07] Addressing misconceptions about weight loss drugs [42:48] Final thoughts and takeaways [48:49] Key ideas (Premium-only) Links/Resources Subscribe to Sigma Nutrition Premium Go to episode page Join the Sigma email newsletter for free Enroll in the next cohort of our Applied Nutrition Literacy course Visit sigmanutrition.com

Zinc is an essential micronutrient that often flies under the radar, despite being vital for hundreds of enzymes and transcription factors involved in immunity, antioxidant defense, and DNA repair. A surprisingly large segment of the population may not get enough – an estimated 10% of U.S. individuals consume less than half the recommended zinc intake, putting them at risk of deficiency. In this episode, Prof. Emily Ho discusses how even mild zinc insufficiency can impair immune function, promote chronic inflammation, and accelerate aspects of aging. She delves into the concept of “inflammaging” – the chronic, low-grade inflammation that develops with age – and explains how inadequate zinc status can aggravate this process. The conversation also highlights emerging research on zinc’s role in DNA integrity and how restoring zinc levels can reverse certain damage, underscoring zinc’s broader significance in healthy aging and disease prevention. Overall, this episode provides a deep scientific look at why maintaining adequate zinc status is crucial for immune resilience and mitigating age-related inflammatory and oxidative damage. About the Guest Emily Ho, PhD is the Director of the Linus Pauling Institute and professor in the College of Health at Oregon State University. Her research focuses on understanding the mechanisms by which nutrient status and healthy foods affect the initiation and/or progression of chronic diseases such as cancer. Her work has helped drive dietary requirements and recommendations for micronutrients such as zinc for communities with susceptibility to poor nutrition. Timestamps [02:10] Interview begins [03:58] The roles of zinc [06:31] Zinc deficiency and insufficiency [14:26] Prevalence and risk factors of zinc deficiency [21:12] Zinc and age-related inflammation [29:39] Zinc’s impact on chronic diseases [31:20] Practical advice on zinc supplementation [41:14] Final thoughts Related Resources Go to episode page (includes related research) Join the Sigma email newsletter for free Subscribe to Sigma Nutrition Premium Enroll in the next cohort of our Applied Nutrition Literacy course Linus Pauling Institute (LPI) Website Micronutrient Information Center Top 10 Micronutrients for Healthy Aging Webinars on LPI YouTube

In this episode, we take a deep dive into the commonly held belief that protein is the most satiating macronutrient. It’s an idea that shows up frequently in both clinical guidance and popular nutrition discourse: if you want to feel fuller, eat more protein. But how robust is that claim when you drill into the details of the evidence? To explore this, Alan and Danny examine the complex interplay between protein intake, satiety, and energy intake. We look at both historical and recent literature, including work from Kevin Hall’s group, that raises important questions about how much of protein’s supposed appetite-suppressing effect is due to the protein itself versus other influential variables—such as eating rate, food texture, and energy density. This is an important topic, not just for academic curiosity, but for its practical implications. If our assumptions about protein and satiety are oversimplified or overstated, that has knock-on effects for how we design diets aimed at appetite regulation, weight management, or obesity prevention. So whether you’re a researcher, a clinician, or simply someone interested in understanding the mechanisms behind how we eat, this episode aims to provide clarity on where the science currently stands—and where it might be leading. Timestamps [03:18] The impact of protein on satiety [04:49] Historical context of protein and satiety [07:30] Mechanisms of protein-induced satiety [16:31] Research methods and measurements [21:39] Studies on protein and satiety [27:51] Analyzing specific studies [35:51] Understanding high protein meals and their effects [37:31] Acute vs. chronic effects of high protein intake [45:59] Other meal characteristics [53:21] Real-world implications of protein intake [01:01:19] Summarizing the impact of protein on satiety Related Resources Subscribe to Sigma Nutrition Premium Join the Sigma email newsletter for free Enroll in the next cohort of our Applied Nutrition Literacy course Go to episode page Related studies: Fazzino et al., Nature Food, volume 4, pages144–147 (2023) Weigle et al., Am J Clin Nutr. 2005 Jul;82(1):41-8 Smeets et al., J Nutr. 2008 Apr;138(4):698-702 Blatt et al., J Am Diet Assoc. 2011 Feb;111(2):290-4.

Global food systems have been increasingly subjected to financial speculation, leading to adverse consequences for growers, consumers, and public health. But what are the systemic vulnerabilities that impact food security, equitable access to nutritious food, and the broader socio-political frameworks influencing these outcomes? Understanding the financial mechanisms shaping food production and distribution is highly relevant for health professionals, policy makers, and researchers concerned with nutrition, equity, and global health systems. This episode urges a critical re-evaluation of current food policies and invites consideration of more ethical, resilient approaches to safeguarding food systems. Professor Martin Caraher is Emeritus Professor of Food and Health Policy at the Centre for Food Policy, City St. Georges, University of London. His research encompasses food poverty, food security, the role of food aid, and the broader implications of food systems on public health. Timestamps [01:12] Financialization of food: an overview [05:27] Speculation and its impact on food prices [13:10] Global food security and policy responses [17:20] Corporate concentration in food systems [34:03] Potential solutions and future directions Related Resources Go to episode page Prof. Caraher’s Recommended Reading List Join the Sigma email newsletter for free Subscribe to Sigma Nutrition Premium Enroll in the next cohort of our Applied Nutrition Literacy course Episode #344: Prof. Martin Caraher – Food Poverty & Food Aid Provision X: @MartinCaraher and @NutritionDanny

Seed oils have recently become a hotly debated topic in nutrition, fueled by sensational claims on social media. In this episode, the central theme is examining whether seed oils are truly harmful or if they’ve been unjustly demonized. The discussion tackles prevalent claims – that seed oils drive inflammation, oxidation, and chronic disease – and compares them against the current scientific evidence. This is highly relevant to nutrition science and clinical practice today, as many patients and practitioners are encountering conflicting information about vegetable oils. By exploring the origins of seed oils, their biochemical effects, health outcome data, and the misinformation ecosystem, the episode aims to clarify how omega-6 rich seed oils fit into a healthy diet and what evidence-based guidelines say. Timestamps 01:00 Understanding terms: PUFA, Linoleic Acid, Omega-6 05:20 Do seed oils cause inflammation? 12:44 Omega-3 and omega-6 16:43 Inflammatory markers and linoleic acid 19:22 Oxidation and cooking oils 26:25 Refining processes and health concerns 30:32 Health outcomes and polyunsaturated fats 35:18 Evidence cited by anti-seed oil proponents 43:48 Conclusions Related Resources Join the Sigma email newsletter for free Subscribe to Sigma Nutrition Premium Enroll in the next cohort of our Applied Nutrition Literacy course Sigma Statement: Seed Oils on Trial: Is the Panic Justified? Related podcast episodes: 502: Sydney Diet-Heart Study – Is Linoleic Acid Causing Heart Disease? 504: Vegetable Oil vs. Saturated Fat – Analysis of the LA Veterans Study 505: Oslo Diet-Heart Study: Cholesterol-lowering Diets & Cardiovascular Events 329: Diet & Inflammation

In this Quack Asylum episode, Danny and Alan critically examine the claims surrounding “detoxification protocols” – specialized diets, cleanses, or supplements marketed to eliminate toxins from the body for better health. The central theme is whether these detox plans actually improve health outcomes or if they’re built on pseudoscience and fear. Many alternative health proponents argue that modern life exposes us to countless toxins that accumulate in our bodies, causing chronic diseases, and thus we must undergo periodic detox regimens to cleanse ourselves. There is genuine concern about environmental pollutants and chemicals – indeed, numerous substances in our food, water, and air can be harmful at sufficient doses​. Nutritional science also recognizes that certain nutrients (e.g. vitamins, antioxidants) play roles in the body’s natural detox pathways. However, there’s a large gap between acknowledging real toxic exposures versus endorsing commercial “detox” diets or products. Many people, including health professionals, encounter patients or clients interested in detox plans, so understanding the science (or lack thereof) behind these claims is important. Timestamps [03:20] Claim 1 – Mark Hyman [06:10] The purpose of today’s episode [08:22] Claim 2 – Chris Kresser [11:30] Detoxification Pathways in the Body [25:46] Glutathione, heavy metals and other nutrients [50:30] Do nutrients support detox pathways [55:20] Unhinged claims: Mold and mycotoxin toxicity [01:04:54] One more unhinged claim [01:09:10] Conclusions Related Resources Subscribe to Sigma Nutrition Premium Join the Sigma email newsletter for free Go to episode page Enroll in the next cohort of our Applied Nutrition Literacy course