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#461: Prof. Emma Boyland – How Food Marketing Impacts Eating Behaviour Nov 22, 2022

Show notes

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.

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SNP11: The Death of Domain Expertise Nov 15, 2022

Show notes

Never before has there been greater access to information about nutrition and health. But never before has there been such a low barrier to being seen as an "expert". There are large numbers of people getting information from, and basing their health decisions on, people who don't have direct expertise in the field in which they are talking about.

Moreover, some promote the lack of domain expertise as a feature, not a bug. They claim that those that were conventionally seen as domain experts are either brainwashed, lazy in their thinking, or outright corrupt. And the solution is instead to look to those with a fresh perspective that can illuminate us on the "truth".

In this episode, Alan and Danny discuss this "death of domain expertise", how it plays out online, and its ramifications for people's ability to get good information.

This is a Premium-exclusive episode. To listen to the full episode and access the transcript, you must subscribe to Sigma Nutrition Premium.

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#460: Dr. Priya Sumithran – Body Fat Regulation, Pros & Cons of Weight Loss Interventions, and GLP-1 Receptor Agonists Nov 08, 2022

Show notes

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.

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#459: Nicky Keay, MB BChir – Hormones & Healthspan: The Endocrine System Across the Life Course Nov 01, 2022

Show notes

The endocrine system plays a central role in growth, development, metabolism, reproduction, and physical well-being throughout life. Hormones interact in complex networks, orchestrating a range of critical functions. Over the life course, we experience various changes in hormone levels, fluctuations, patterns, and actions. Additionally, lifestyle factors and disease processes can impact the levels and functions of hormones.

In this episode, Dr. Nicky Keay, a medical doctor with expertise in the field of exercise endocrinology, is on the podcast to discuss a variety of endocrine-related issues, including: hormone diurnal variation, bone health, amenorrhoea, HRT, perimenopause, and thinking about hormones and aging.

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What Are Stable Isotopes? How Are Tracers Used in Nutrition Research? (Preview) Oct 25, 2022

Show notes

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.

#458: How Foods Impact Satiety, Hunger & Appetite Oct 18, 2022

Show notes

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.

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#457: Austin Robinson, PhD – Salt Sensitive vs Salt Resistant, Impacts of Sodium on Health, & Racial Differences in Risk Oct 11, 2022

Show notes

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:

#456: Prof. Glenn McConell – Glucose Uptake During Exercise & Muscle Insulin Sensitivity Oct 04, 2022

Show notes

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.

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#455: Jill Joyce, PhD – Improving the Diets of Tactical Populations Sep 27, 2022

Show notes

The term 'tactical populations' has been applied to those working in law enforcement, fire, first responders, and military. In addition to the importance of their work, the work they do itself presents some challenges for health and nutrition.

Despite the fact that such individuals make up a significant number of the population and their work plays a crucial role in society, there is currently very little research on fire and law enforcement nutrition. Most research is on the prevalence of disease and the occupational risk factors and related pathophysiology. Lifestyle research, descriptive and interventions, is way behind.

Dr. Jill Joyce is the co-director of the OSU Tactical Fitness and Nutrition Lab at Oklahoma State University. She does research looking at real-world interventions in these populations, particularly firefighters, in an attempt to improve their diets and health.

In this episode, we look at both the theoretical and pragmatic realities of improving diet and health in firefighters and some other tactical populations.

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SNP9: AMA – Blood Pressure, LDL Lowering, PCOS & More! Sep 20, 2022

Show notes

In this Premium-exclusive 'Ask Me Anything' episode, Alan & Danny answer a range of listener questions. Topics include obesity rates, lowering blood pressure, cholesterol drugs, PCOS, and what issues they have changed their minds on. See the full list of questions below. [02.37] Do you feel that there is hope (or an effective way forward) for obesity rates to come down? Based on your response, why/why not? [11.28] In this field, it seems like so many of us have had positions we've held very seriously that we now see as poorly supported by research, or just have a significant paradigm change. It would be great to hear you look back to how your views have evolved over the years. [30.34] Apart from lowering salt intake and eating foods high in potassium are there other things you can take or do to reduce blood pressure? [40.34] What is the best ratio of DHA vs EPA to increase my Omega 3 index? [46.20] Statins v Ezetimibe: Differences between the two? Mechanism of action? Are there situations, conditions, genetic markers where one may work better than the other? [56.20] I'm starting a PhD in the fall concerning the pathophysiology of metabolic diseases and I'd like to take some courses that would help me in my research. Would you have any recommendations for a beginner scientist? [59.01] Is astaxanthin a good substitute for algae oil for someone who follows a vegan diet? [60.45] Do you have any suggestions how to better manage hunger in obese women with PCOS? [64.33] Do you have any recommendations for anyone wanting to get involved in chrononutrition research? Links:

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