Sigma Nutrition Radio

Creatine is best known as a sports supplement for enhancing muscle strength and high-intensity performance. But could it also improve brain health and cognitive function? Or are such claims overhyped?

If creatine can support brain health, it could have implications for aging, neurodegenerative diseases, concussion recovery, and mental fatigue.

In this podcast episode, Professor Eric Rawson discusses what current science says about ...

Energy expenditure is one of the most fundamental yet often misunderstood aspects of human physiology. A central question is whether there is a ceiling to how many calories we can burn, and what happens when activity levels approach that limit. Grasping these dynamics is essential for health professionals and researchers, as energy balance directly influences body weight regulation, metabolic health, and athletic performance.

Emerg...

Recently a new trial was published in Nature Medicine comparing the effect of ultra-processed versus minimally processed diets. Specifically, the UPDATE trial compared these two diets in the context of a healthy dietary pattern (in line with the UK’s EatWell Guide).

This eight-week randomized, crossover trial generated a lot of discussion and was largely seen as being a really useful addition to the evidence base, and providing ans...

In this episode, Dr. Matthew Facciani explores how social psychology influences health beliefs and the spread of misinformation. The conversation delves into why people adopt certain nutrition or health beliefs so strongly, how identity and group membership shape our interpretation of evidence, and what makes us susceptible to false or misleading health claims.

Dr. Facciani’s interdisciplinary background (spanning neuroscience, psy...

Dairy is often treated as a single food group, yet milk, yogurt, cheese, and butter can have very different effects on health. Some evidence links yogurt to favourable outcomes, while butter is known to raise LDL cholesterol. And then there’s the paradox of cheese: high in saturated fat, but not consistently associated with higher heart disease risk.

These complexities raise the question of whether the “dairy matrix” (the combinati...

They’re in our oceans, our air, our food, and now even in our bodies. Microplastics, once a distant environmental issue, have become a topic of urgent relevance in medicine, public health, and nutrition. The idea that tiny plastic particles are circulating through the food chain and accumulating in human tissues has sparked headlines, speculation, and concern. But how much of this fear is grounded in solid science? And how much is ...

In this episode, performance nutritionist Daniel Davey discusses how his approach to elite sports nutrition has evolved over his career. Davey reflects on his decade working with top Irish teams (Dublin GAA/football and Leinster Rugby) and how stepping away from those environments led him to rethink the role of a nutrition practitioner. 

The central theme is a shift from a traditional prescriptive model, where the expert provides m...

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...