Sigma Nutrition Radio

Neurodegenerative disease and obesity neuroscience expert, Stephan Guyenet, PhD, answers questions on the impact of liposuction on hunger, effects of chronic energy restriction on appetite hormones, dysregulation versus normal regulation of body mass, and the benefits of Sigma Nutrition Premium.

Climate change refers to long-term shifts in temperatures and weather patterns. These shifts may be natural, such as through variations in the solar cycle. But since the 1800's, human activities have been the main driver of climate change, primarily due to burning fossil fuels like coal, oil and gas. Climate change has the potential to negatively impact the nutrient value of plants, soil organisms, food stuffs, via a variety of ways. Climate change puts food supplies at risk. Floods, droughts, more intense hurricanes, heatwaves and wildfires can drive down crop yields, destroy livestock, and interfere with the transport of food. And rising carbon dioxide levels from human activity can make staple crops like rice and wheat less nutritious. In this podcast the Sigma team take a look at the evidence on how climate change will impact nutrient status, if left unchecked. There will be also a look at what solutions have been put forward to tackle this issue. This episode will focus more on how climate change impacts nutritional & nutrient status, as opposed to converse (but equally important) issue of how food systems impact climate change. Access show notes here Subscribe to Premium here Attend a live event in London, Dublin or Berlin!

When it comes to specific questions related to diet and health for women, there is often a shortage of consensus answers from research, for a variety of reasons. In addition, there are clearly aspects of biological sex that have implications for health and also the interaction with diet. For example, the impact of the menstural cycle, of menopause, and differences in nutrient requirements. In this episode, Dr. Hazel Wallace discusses some of these key considerations. Some things covered include: the impact of menstrual cycle phase on cravings, at-risk nutrients in pre-menopausal women, functional hypothalamic amenorrhea, interaction of diet and PMS, the physiological changes at menopause and potential role of diet. Click here for show notes to this episode Click here for Premium Click here for live event details

This is a preview of the second episode in a new series called "Nutrition Science Explained", in which members of the Sigma team will take a concept commonly mentioned in discussions about nutrition science, and explain what it is, give more background context, and highlight important aspects to know. The goal is to aid listeners to have a deeper understanding of other episodes when such concepts are mentioned. In this episode Alan Flanagan discusses the concept of the GRADE system, and specifially how it applies to evaluating nutrition research and coming to conclusions for practice. GRADE (Grading of Recommendations, Assessment, Development and Evaluations) is a framework for developing and presenting summaries of evidence and provides a systematic approach for grading the quality of evidence and making clinical practice recommendations. In order to listen to the full episode, you will need to subscribe to Sigma Nutrition Premium.

Folate (also known as viatmin B9) actually relates to a collection of folates; both natural dietary folates and synthetic forms, primarily folic acid. This folate/folic acid that is consumed via the diet or supplementation is a precursor for the formation of tetrahydrofolate (THF), which is a carbon donor and acts a cofactor for a number of enzymes that play important roles in several processes. In this episode, Alan and Danny discuss the role of folate in the methlyation cycle, the impact of folate insufficiency/deficiency, genetics variatnts of the MTHFR gene (and other genes) that impact folate metabolism, and the impact of folate on health outcomes; including heart disease, birth defects, cancer, and brain health & cognition. Detailed study notes and transcript to this episode

A recently published study by Klatt and colleagues examined the impact of choline supplementation alongside DHA supplementation, versus DHA supplementation alone, on DHA status in pregnancy. It is known that DHA is a critical nutrient at this time for healthy development of the child. And through a number of mechanisms discussed later, it has been hypothesized that choline could lead to greater DHA status. We discuss: What is the connection between choline and DHA? What is the PEMT pathway? Study design for the choline + DHA trial Are there risks of high-dose choline? Main findings of the trial How DHA status is not just a function of DHA intake, but also methyl metabolism too Issues with omega-3 trials; e.g. not taking baseline status into account Pragmatic recommendations for health professionals and patients Different forms of choline supplements Choline supplementation vs. food-derived choline Access the show notes here Subscribe to Premium here

In this episode Alan and Danny aim to address the idea that you shouldn't eat vegetables, or that they aren't beneficial. We will specifically look at a number of claims that relate to: The claim that vegetables aren't beneficial for health, or that there is no health benefit to high vegetable intake. The claim that vegetables are actually detrimental to health, and their removal improves health. This episode was orignally published to Sigma Nutrition Premium. If you wish to get more of these Quack Asylum episodes (and lots of other features, including detailed study notes) then subscribe to Sigma Nutrition Premium. Click here to access show notes

This is an "ask me anything" (AMA) episode, with Prof. Stuart Phillips of McMaster University. Prof. Phillips takes questions on protein intake, sources, muscle function, and healthy ageing. To listen to the full AMA, click here to subscribe to Sigma Nutrition Premium. Questions answered: [04.28] What is muscle protein balance? [05.32] Why is the focus always on muscle protein synthesis? [07.14] Is MPS a good proxy measure for outcomes we care about (e.g. muscle growth/repair)? [10.37] What's the difference between 'whole body protein synthesis' and 'muscle protein synthesis'? [12.57] We're starting to see commercially available whey that has been produced by bacteria engineered to synthesize whey protein directly from nutritional substrate. It seems like we should expect this to have directly comparable effects given the identical molecular structure. Is there any reason to think this bacterially synthesized whey will have any different effects that whey from dairy? [15.50] Does the literature still show that an additional dose of plant-derived protein is required to equate a similar response from animal protein? [26.39] During post-exercise conditions does protein ingestion stimulate MPS for longer than the usual 2-3 hour period reported in rested conditions? [27.49] Considering the growing interest in fasting protocols (both TRF and longer fasting protocols) - what would you recommend in these circumstances for the preservation / growth of muscle mass. Would it differ between IF/TRF and longer (1-3 day) fasts? [34.58] Is it a waste to take too much protein powder at once because some of it won't get absorbed? [42.50] Does protein powder lose some of its quality if boiling water is added due to protein denaturation? [47.05] Would you please share your opinion about how you evaluate protein status in the body? [50.51] I am now over 60 and lift heavy twice a week. What would be a reasonable body fat % for me to aspire to and how much daily protein should I be targetting in my diet? Subscribe to Premium

Consuming a healthy diet during pregnancy is an obvious and accepted recommedation. However, what exactly is a "healthy diet" in this context? In addition, there are specific nutrients which are crucial for the healthy development of the child, including nutrients which may be difficult to consume enough of. In addition there are nutrients and foods that need to limited or avoided during this period. In this episode, researcher and dietitian Dr. Julie Abayomi discusses important nutrients in pregnancy (e.g. iodine, DHA, and folic acid), as well as potentially problematic nutrients/foods (e.g. high-mercury fish and caffeine). In addition, she discusses the current debates about weight gain/loss during pregnancy, as well as what supports are needed for health professionals supporting pregnant women. Click here for show notes Subscribe to Premium

It has become common rhetoric for those promoting various types of diets to suggest that dietary guidelines published by government departments are at best, unhealthy, or at worst, causative in driving obesity and chronic disease in the population. While different countries and organizations produce their own guidelines, with slight differences, most of the conversation has focused on the Dietary Guidelines for Americans, that are created by the USDA. Often the claims is that following these guidelines actually harms health, rather than promote it. And the guidelines are simply a result of industry forces, long-standing bias, and shoddy science. But do these claims hold up to scrutiny? In this episode Alan and Danny look at some of the arguments put foward, and take a look at the science underpinning dietary guidelines in a number of countries. In this episode: [0.01.46] Examples of arguments put forward stating that it's not healthy to follow dietary guidelines [0.12.50] History of the development of guidelines in the US & narratives around Ancel Keys [0.23.50] Misrepresentation of what the guidelines say [0.30.49] What are actually in the current Dietary Guidelines for Americans? [0.33.10] Changes to guidelines over time [0.36.05] Other countries' guidelines: UK, Canada, Nordic countries [0.40.50] Investigating the rise in obesity/disease prevalence with the roll out of the guidelines [0.56.34] Do people follow the guidelines? [1.00.01] The negative role of the food industry [1.03.50] Potential issues with dietary guidelines Links: Subscribe to Premium Show notes to this episode