Sigma Nutrition Radio

In this episode, the Sigma team explores the question: "Do vegan diets increase the risk of depression?" This is a question that emerges from a few different places. First, it's common to hear such a claim from proponents of largely animal-based diets. Some reference is often made about how vegan diets can, at best, worsen symptoms or, at worst, even cause depression. Or conversely, they may state that moving away from a plant-based diet will improve mental health outcomes, including depression. And while all of those specific claims aren't within the scope of this episode, such claims do get people wondering if a plant-exclusive diet is actually a cause of various mental health ailments. But is there a basis for such claims? In this episode, we explore the evidence from two ends: 1) research related to the proposed mechanisms by which a vegan diet could cause problems, and 2) outcome data looking at the impact of such diets. Links: Subscribe to Premium Episode notes page Live event: London, UK (early bird ends Dec 19)

Gyorgy Scrinis, an expert on ultra-processed foods and their effects on nutrition and food systems, dives deep into the complexities of our modern diets. He discusses the Nova food processing classification system and its implications for health, advocating for a holistic understanding beyond mere nutrients. The conversation highlights the socioeconomic factors driving the rise of ultra-processed foods, particularly in disadvantaged communities. Scrinis emphasizes the need for systemic changes in public policy to tackle food poverty and inequality, making it clear that nutrition is intricately linked to broader social issues.

Research has shown that food marketing strongly impacts children's eating behaviour. Marketing influences food purchase requests, purchases, and preferences. And the evidence of a relationship between food marketing exposure and obesity meets epidemiological criteria for causality. The evidence suggests that the impact of food marketing is a function of both exposure to the marketing message and its persuasive power. What does the current evidence tell us about the exact effect of marketing on food choices? And beyond that, what strategies are likely to yield the best results in terms of mitigating the harms of food marketing on eating behaviour, particularly in children and adolescents? To help answer these questions, subject area expert Prof. Emma Boyland is on the podcast to discuss what is currently known. Links: Episode page, resources & links Subscribe to Premium

The podcast explores the alarming trend of undermining true expertise in nutrition. It discusses how influential online voices often lack genuine knowledge, complicating the landscape for those seeking reliable health information. The hosts emphasize the importance of domain-specific expertise, warning against oversimplified critiques of complex nutritional studies. They also highlight the dangers of entertainment-focused platforms as sources of health information, stressing the need for informed decision-making in the digital age.

Obesity increases the risk of a range of chronic diseases and negative health outcomes. And trials where a sufficient amount of weight loss is achieved show health improvements. However, despite the "straightforward" nature of causing weight loss through a hypocaloric diet, it is clear that most people who lose weight will regain some or all of the weight. This is a result of both the physiologic control of intake and expenditure (i.e. homeostatic regulation by the body to avoid staying at a lower body or fat mass), and environmental factors. Diet-induced weight loss is followed by a number of hormonal change that encourage weight regain. So how do we tackle this problem? In this episode, Dr. Priya Sumithran discusses this physiologic control of body mass, in addition to environmental and behavioural factors that make weight loss maintenance difficult. Dr. Sumithran also discusses what this means for setting weight loss targets, choosing the correct intervention, and looking to non-weight-centric approaches for certain individuals. We also discuss the evidence on GLP-1 receptor agonist drugs, such as Semaglutide, as a treatment for obesity. Links: Episode page Subscribe to Premium Sigma live event - Berlin Sigma recommended resources

Dr. Nicky Keay discusses hormone diurnal variation, bone health, amenorrhea, HRT, perimenopause, and aging implications in the context of the endocrine system across different life stages. The intricacies of hormones, importance of timing in hormone testing, and maintaining hormonal balance through lifestyle interventions are emphasized.

Stable isotopes have been used as tracers in human nutritional studies for many years. But what are they? Why do we use 'tracers' in nutrition studies? And what are some practical examples? A chemical element can have different forms or 'isotopes.' These different isotopes have the same atomic number and position in the periodic table but have different atomic masses and physical properties. An isotope that is not radioactive is said to be 'stable'. In physiology and metabolism research, stable isotopes are used as 'tracers.' As the name implies, it allows us to 'trace' the fate of compounds, thus giving a very detailed insight into the metabolism of nutrients and the regulation of many disease processes. In this episode, Dr. Alan Flanagan explains what stable isotope tracers are, how they are used to answer nutrition science questions and some examples that you may come across. This is a 'Nutrition Science Explained' episode. These episodes are exclusive to Sigma Nutrition Premium. To listen to the full episode and access the transcript, you must subscribe to Sigma Nutrition Premium.

Given the negative consequences of consistent overconsumption of food (leading to a caloric surplus), having a dietary intake that is of appropriate calorie intake is an important aspect of long-term health. Therefore, thinking about which foods and diets can help promote appropriate satiety to keep calorie intake in check is a key focus for many researchers and practitioners. There is a complex system of human appetite control. This appetite system influences food consumption and associated motivational drives such as hunger, as well as interacting with and being influenced by energy expenditure. Satiety is an important psycho-biological process involved in the expression of human appetite, inhibiting hunger and intake following food or beverage consumption. In this episode, the Sigma team discusses the human appetite system, how different nutrients and foods impact satiety, and the implications of this research. Links: Subscribe to Premium Show notes for this episode Live event in Berlin, Germany Sigma Recommended Resources

Hypertension (elevated blood pressure) is a condition that significantly increases the risk of several diseases and is a major cause of premature death worldwide. In the US, recent estimates suggest that about half of the adult population has hypertension. At a population level, high sodium intake is one of the main dietary risk factors. All population health guidelines recommend keeping sodium intake below certain levels. While, on average, blood pressure correlates with sodium intake, there is a wide range of responses on an individual level. People who see increasing sodium intake lead to increased blood pressure are termed "salt sensitive". Others, however, don't see much change in blood pressure with increased dietary sodium. Such individuals are classed as "salt resistant". In this episode, Assistant Professor at Auburn University, Dr. Austin Robinson, is on to discuss whether people who are salt resistant need to keep their sodium intake low or not. And other individual and group differences that exist for hypertension risk and sodium physiology? Links: Subscribe to Premium Episode overview Live event in Berlin Recommended Resources

Exercise improves metabolic control both via increasing muscle glucose uptake during muscle contractions by insulin-independent mechanisms and by increasing skeletal muscle insulin sensitivity after physical activity. A reduction in skeletal muscle insulin sensitivity is an early event in the development of not only prediabetes, metabolic syndrome, and type 2 diabetes but is also associated with other conditions such as cardiovascular disease and some cancers. One of the researchers that has been at the forefront of research in this area for many years is Professor Glenn McConell. In this episode we discuss glucose uptake during and after exercise, looking at both insulin-dependent and insulin-independent mechanisms. In addition we discuss the crucial importance of muscle insulin sensitivity and some important research breakthroughs on the topic. Links: Subscribe to Premium Episode show notes Live event: Berlin