ZOE Science & Nutrition

Today we’re talking about the immune system.

It’s one of the most important systems in our body, yet it’s also one of the hardest to understand. You can’t see it, you can’t feel it working, and there’s no simple way to measure whether it’s strong or weak.

But when it fails, we certainly notice.

Everywhere we look, supplements and superfoods promise to ‘boost’ our immune system. But how many of these claims are actually supported by science?

Professor Daniel Davis joins me to explain how our immune system truly works, and what the evidence says is the best ways to support it.

🌱 Try our science-backed and tasty wholefood supplement Daily30

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📚Books by our ZOE Scientists

The Food For Life Cookbook

Every Body Should Know This by Dr Federica Amati

Food For Life by Prof. Tim Spector

Ferment by Prof. Tim Spector

Good Mood Food (preorder) by Prof. Tim Spector

Free resources from ZOE

The Hormone Harmony Guide: Tuning Your Body’s Internal Orchestra

Eating for Better Brain Health: Your brain-gut blueprint

How to eat in 2026 - Discover ZOE’s 8 nutrition principles for long-term health

Live Healthier: Top 10 Tips From ZOE Science & Nutrition

Gut Guide - For a Healthier Microbiome in Weeks 

Better Breakfast Guide

Have feedback or a topic you'd like us to cover? Let us know here.

Episode transcripts are available here.

1 in 4 people have insulin resistance, which quietly raises your risk of heart disease and cancer, often without any change in your blood sugar.

And most of those who have it have no idea. It can remain completely hidden for years, with no obvious symptoms and no warning signs… But it can be reversed.

Today, Professor Rob Semple, a world-leading expert on insulin resistance, explains what insulin does in your body, why you need it to live, and what happens when it stops working properly.

By the end of this episode, you will understand how to spot the warning signs and have practical steps you can take to protect yourself.

If your last blood test came back "normal," how confident are you that it tells the whole story? Are you overlooking one of the biggest drivers of chronic disease?

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Timecodes

00:00 Intro

00:46 Why insulin might be the most important hormone in your body

01:53 What happens if your body stops making insulin

05:20 Why not having insulin used to be a death sentence

11:19 What happens to your brain when blood sugar drops too low

14:01 Why "just lower your insulin" advice can backfire

17:12 The shaky, sweaty feeling an hour after eating, explained

18:42 The exact moment insulin resistance turns into diabetes

21:47 Why high insulin can affect your ovaries

24:15 A visible skin sign that insulin levels are too high

25:40 The organs most at risk when blood sugar spirals

27:17 How common insulin resistance really is in the US and UK

30:23 Why your ovaries can be an early sign of insulin resistance

32:49 Debunking the online "signs" of insulin resistance

35:37 Is insulin resistance actually reversible?

36:47 Why your weight matters more than your BMI number

38:53 The DEXA scan that revealed hidden visceral fat

41:14 Why white bread might not be so different from a can of Coke

43:56 Why one type of exercise burns blood sugar best

45:17 Do you really need two hours in the gym to see results?

46:38 How stress directly changes your blood sugar

48:32 Why irregular sleep might be hurting your blood sugar

49:38 The one piece of advice for anyone worried about insulin resistance

55:00 Why insulin resistance may have once been a survival advantage

📚Books by our ZOE Scientists

The Food For Life Cookbook

Every Body Should Know This by Dr Federica Amati

The Appetite Reset by Dr Federica Amati

Food For Life by Prof. Tim Spector

Ferment by Prof. Tim Spector

Good Mood Food (preorder) by Prof. Tim Spector

Free resources from ZOE

The Smart Snacking Guide: How to feed your gut, fuel your day, and snack without guilt

The Hormone Harmony Guide: Tuning Your Body’s Internal Orchestra

Eating for Better Brain Health: Your brain-gut blueprint

How to eat in 2026 - Discover ZOE’s 8 nutrition principles for long-term health

Live Healthier: Top 10 Tips From ZOE Science & Nutrition

Gut Guide - For a Healthier Microbiome in Weeks

Better Breakfast Guide

Mentioned in today's episode

Insulin resistance is a risk factor for 12 types of cancer, Nature (2026)

Association of insulin resistance with cancer, American Journal of Cancer Research (2016)

Global prevalence of insulin resistance, Frontiers in Endocrinology (2025)

Risk Reclassification Beyond BMI, (JACC) (2026)

Have feedback or a topic you'd like us to cover? Let us know here.

Episode transcripts are available here.

Today we’re talking about food additives.

Take a look at the back of some ultra-processed packaged food and you’ll see a long list of unfamiliar ingredients. Complex, sciencey sounding names that most of us can barely pronounce.

These are called additives. But what exactly are they? How are they tested? And, most importantly, are they truly safe for us to eat?

Food policy expert Professor Marion Nestle joins me to explore how additives became so deeply embedded in modern food production — and why, now more than ever, it’s essential for you to understand the things that are hiding in your food.

🌱 Try our science-backed and tasty wholefood supplement Daily30

Get our brand-new app and Gut Health Test designed by world-leading gut health and nutrition scientists to build healthy eating habits 👉 Join ZOE

Follow ZOE on Instagram.

📚Books by our ZOE Scientists

The Food For Life Cookbook

Every Body Should Know This by Dr Federica Amati

Food For Life by Prof. Tim Spector

Ferment by Prof. Tim Spector

Good Mood Food (preorder) by Prof. Tim Spector

Free resources from ZOE

The Hormone Harmony Guide: Tuning Your Body’s Internal Orchestra

Eating for Better Brain Health: Your brain-gut blueprint

How to eat in 2026 - Discover ZOE’s 8 nutrition principles for long-term health

Live Healthier: Top 10 Tips From ZOE Science & Nutrition

Gut Guide - For a Healthier Microbiome in Weeks 

Better Breakfast Guide

Have feedback or a topic you'd like us to cover? Let us know here.

Episode transcripts are available here.

There's a hidden fat that matters more for your health than your weight. This is visceral fat: it wraps around your organs, raises your risk of heart disease and cancer, and builds up even in people who look slim and healthy.

In today’s episode, Professor Jimmy Bell, a world-leading expert in measuring visceral fat, explains how we can shrink this dangerous belly fat in just 12 weeks.

Jimmy explores why two people can weigh exactly the same and carry completely different amounts of this hidden fat, what it is, where it hides and why it matters.

By the end, you'll have a completely new understanding of body fat, and what it really means for your long-term health.

If your weight has stayed exactly the same for years, what do you think is happening underneath it?

🌱 Try our science-backed and tasty wholefood supplement Daily30

🌿Let your gut microbes snack on the ZOE Gut Health Bar

Build healthy habits. Download the ZOE app today and start your trial for just £2.30 for your first week. 👉 Join ZOE

Follow ZOE on Instagram.

Timecodes

00:00 Intro

02:47 The DEXA scan result that didn't match how thin he looked

09:46 Why your body composition can get worse even while your weight stays the same

11:47 What does it actually mean to be "skinny fat"?

14:06 The real reason some people end up "skinny fat"

15:58 Why people carrying more fat might actually be happier

18:10 How visceral fat sends inflammatory signals through your body

21:50 Why having almost no body fat can also make you unhealthy

25:19 Could a supermodel have more visceral fat than a sumo wrestler?

26:44 Why your body stores visceral fat around your organs on purpose

28:08 Why visceral fat is the first fat to disappear when you diet

29:22 How your diet directly reshapes the fat in your body

33:25 How long it actually takes to change your body fat

35:47 Does Ozempic actually get rid of visceral fat?

37:05 Why dieting alone can quietly cost you muscle

38:55 What does yo-yo dieting actually do to your body?

41:20 The pattern he sees again and again in long-term dieters

42:39 Why being thin is no guarantee you don't have visceral fat

44:07 Why diet alone won't get rid of visceral fat

45:24 The exact mechanism that makes exercise target visceral fat first

49:03 Why inflammation and visceral fat together wreck your metabolism

49:50 Why any amount of alcohol is bad news for visceral fat

51:32 How fast visceral fat can actually shrink (as little as 12 weeks)

54:14 Why menopause redistributes fat to your belly

57:20 Resistance training: the single best thing for visceral fat

📚Books by our ZOE Scientists

The Food For Life Cookbook

Every Body Should Know This by Dr Federica Amati

The Appetite Reset by Dr Federica Amati

Food For Life by Prof. Tim Spector

Ferment by Prof. Tim Spector

Good Mood Food (preorder) by Prof. Tim Spector

Free resources from ZOE

The Smart Snacking Guide: How to feed your gut, fuel your day, and snack without guilt

The Hormone Harmony Guide: Tuning Your Body’s Internal Orchestra

Eating for Better Brain Health: Your brain-gut blueprint

How to eat in 2026 - Discover ZOE’s 8 nutrition principles for long-term health

Live Healthier: Top 10 Tips From ZOE Science & Nutrition

Gut Guide - For a Healthier Microbiome in Weeks

Better Breakfast Guide

Mentioned in today's episode

Fat cell turnover in humans, Nature (2008)

New study investigates ‘optimal’ diets for healthy aging

Study of visceral, subcutaneous, liver and pancreas fat changes after 12 weeks, Diabetes Research and Clinical Practice (2023)

MRI assessment of adipose tissue fatty acid composition, Obesity (2024)

Phenotyping, Body Composition, and Precision Nutrition (2024)

Have feedback or a topic you'd like us to cover? Let us know here.

Episode transcripts are available here.

Today we’re talking about sleep.

The more scientists study sleep, the clearer it becomes that it’s not just about resting our bodies - it’s much more than that. In fact, sleep is the foundation upon which a healthy diet, exercise, and overall wellbeing are all built upon.

So what happens when that foundation is shaky?

Recent research suggests that poor sleep quality may significantly increase your risk of heart disease and even heart attacks.

Dr. Nour Makarem joins me to explore the powerful connection between sleep and heart health - and why both too little and too much sleep is a cause for concern.

🌱 Try our science-backed and tasty wholefood supplement Daily30

Get our brand-new app and Gut Health Test designed by world-leading gut health and nutrition scientists to build healthy eating habits 👉 Join ZOE

Follow ZOE on Instagram.

📚Books by our ZOE Scientists

The Food For Life Cookbook

Every Body Should Know This by Dr Federica Amati

Food For Life by Prof. Tim Spector

Ferment by Prof. Tim Spector

Good Mood Food (preorder) by Prof. Tim Spector

Free resources from ZOE

The Hormone Harmony Guide: Tuning Your Body’s Internal Orchestra

Eating for Better Brain Health: Your brain-gut blueprint

How to eat in 2026 - Discover ZOE’s 8 nutrition principles for long-term health

Live Healthier: Top 10 Tips From ZOE Science & Nutrition

Gut Guide - For a Healthier Microbiome in Weeks 

Better Breakfast Guide

Have feedback or a topic you'd like us to cover? Let us know here.

Episode transcripts are available here.