Sigma Nutrition Radio

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 a...

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 abil...

Fructose has often been labeled a uniquely damaging nutrient, blamed for obesity, diabetes, and other metabolic diseases. But does fructose truly have unique harmful effects or are the risks associated with it related to context and quantity?

The episode explores how fructose is metabolized in the body, why it gained a reputation for being problematic, and what the scientific evidence says about fructose in our diets. You will gain...

Vitamin A is often one of the less-discussed micronutrients in relation to bone health, taking a back seat to nutrients like calcium and vitamin D. Yet this fat-soluble vitamin plays a fundamental role in skeletal development, remodeling, and mineral homeostasis. It influences gene expression in both osteoblasts and osteoclasts, and contributes to the regulation of bone turnover throughout the lifespan.

But what makes vitamin A par...

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 ...

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 re...

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...

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 ...

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 aft...

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 ho...

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, an...

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 h...

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 nut...

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 toxi...

Emulsifiers are a ubiquitous component of the modern food supply, found in everything from salad dressings and dairy products to pastries and sauces. Traditionally regarded as safe by regulatory agencies, emulsifiers play a vital role in enhancing the texture, stability, and shelf-life of countless processed foods.

Yet, in recent years, emerging research has prompted a reevaluation of this assumption, raising intriguing questions a...

Nutrition is increasingly being considered as a modifiable factor that may influence neurodevelopmental outcomes. While severe deficiencies in certain nutrients are known to have dramatic effects, there is growing interest in the potential impact of more subtle insufficiencies — particularly during critical windows such as pregnancy, infancy, and early childhood.

In conditions like ADHD, dyslexia, and autism spectrum condition (ASC...

This is a segment from one of our Premium-exclusive AMA (ask me anything) episodes, where we answer questions submitted by Premium subscribers.

To listen to the full episode, you’ll need to be a Premium subscriber and access the episode on the private Premium feed.

Questions Answered in This Episode

• [02:00] Why does the Mediterranean diet emphasize monou...

The intersection of nutrition, dermatology, and skin health is an area of growing interest, yet one that remains riddled with misinformation and oversimplified claims.

The influence of dietary patterns, specific nutrients, and lifestyle factors on conditions such as acne, eczema, psoriasis, and skin aging has been widely debated, with varying levels of evidence supporting different interventions.

While some nutritional strategies m...

Discussions around ultra-processed foods (UPFs) and their role in public health have gained significant traction in recent years. While some advocate for categorizing and regulating these foods due to their potential negative health effects, others argue that such classifications can oversimplify the issue and detract from more actionable dietary changes.

In this episode, Dr. Duane Mellor, a registered dietitian and researcher, joi...