The science behind food that isn’t food, why you love it and why you should not fear it all | Prof Tim Spector & Prof Sarah Berry

Are some of your "healthy" foods actually high-risk ultra-processed foods? 

For decades, nutrition advice seemed relatively straightforward. Eat less sugar. Less salt. Less saturated fat. Then it all fell apart.

In today’s episode, we examine the research that has forced us to rethink what makes food harmful in the first place. Two of the world’s leading nutrition scientists, Professor Tim Spector and Professor Sarah Berry, tell their own story of why they’ve changed their minds about it.

We explore why sugar, salt and fat aren’t the whole story, explain why ultra-processed foods are making us sick, and share groundbreaking insight that only a small portion of them are really harmful.

By the end of the episode, you’ll know what to watch out for and what to worry less about when you’re food shopping.

Next time you reach for a "healthy" yogurt or a quick pasta sauce, would you still choose it if you knew exactly how it was made?

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Timecodes

00:00 Intro

02:24 The biggest myth about spotting ultra-processed food

07:52 How much of your diet is actually ultra-processed

12:09 Why people ate 500 more calories on ultra-processed food

13:47 The study that changed how scientists see ultra-processed food

17:52 The hidden artificial sweeteners nobody noticed they were eating

20:29 What sweeteners did to mice in this gut bacteria experiment

23:57 What emulsifiers might be doing to your gut lining

28:27 Why food additive combinations are impossible to track

31:30 Can food texture alone change how much you eat?

33:08 Two ultra-processed diets, 369 calories apart

37:10 How the tobacco industry invented food's "bliss point"

39:33 Why hyperpalatable food makes you eat the whole bag

42:17 Does skipping cakes and soda avoid ultra-processed food?

46:38 The "ultra-processed" foods that are actually protective

48:32 How ZOE built its own ultra-processed food risk score

51:01 Why 72 calories a minute is one sign of a risky food

53:48 The 25% of ultra-processed food causing most of the harm

56:11 The one-question test for spotting ultra-processed food

59:32 ZOE says 25% of food is high risk, not NOVA's 60%

01:01:54 Why some "healthy" yogurts are full of hidden sweeteners

01:03:16 Why children's food is designed to make kids overeat

01:05:41 Two pestos, one full of hidden sweeteners

01:10:20 Ultra-processed food uses the same trick as cigarettes

01:11:41 Why you shouldn't fear all processed food

📚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

Ultra-Processed Diets Cause Excess Calorie Intake and Weight Gain, Cell (2019)

Personalized microbiome-driven effects of sweeteners, Cell (2022)

Food Emulsifiers and Metabolic Syndrome: The Role of the Gut Microbiota, Foods (2022)

NutriNet-Santé Study

Eating rate has sustained effects on energy intake from ultraprocessed diets, The American Journal of Clinical Nutrition (2026)

The role of hyper-palatable foods in energy intake, Eating Behaviours (2025)

ZOE’s PREDICT studies: What we’ve learned

Episode transcripts are available here.