Bad Idea #33 "Ultra Processed Foods are killing us’" with Sarah Berry

About this episode

🔍 Episode Summary:

Is the food industry slowly killing us? Is processing of food the problem? Do we really need personalized nutrition? In this episode of Saving the World from Bad Ideas, Mark Lynas sits down with Professor Sarah Berry — nutritional scientist and Chief Scientist at ZOE — to take on Bad Idea #33: “Ultra Processed Foods are killing us”

From the gut microbiome to micronutrients, ultra-processed foods, polyphenols, insulin resistance, fats, carbs, and the myth of the “perfect diet,” Sarah explains why individuals respond so differently to the same foods — and why population-level dietary guidelines often fail to deliver.

They dig into the largest personalised nutrition study in the world, break down the science behind metabolic health, explore why the food environment keeps pushing us toward unhealthy choices, and examine how AI, big data, and microbiome analysis could revolutionise how we think about food.

🧠 Topics Discussed:

● 🧬 Why one-size-fits-all nutrition fails

● 🍽️ What personalised nutrition actually means (and doesn’t mean)

● 🧪 The PREDICT studies — the world’s largest personalised nutrition programme

● 🦠 Gut microbiome diversity: why it matters

● 🔬 Ultra-processed food: what the science really shows

● 🧁 Why sugar behaves differently in different bodies

● 🧂 Salt, fats, omega-3s, fibre, polyphenols — a practical breakdown

● 🧠 Why “calories in, calories out” isn’t enough

● 🏥 Why metabolic health is declining (and what to do about it)

● 🧘 How sleep, stress, and exercise influence food responses

● 🤖 How AI and microbiome data could shape the future of nutrition

👩‍🏫 Guest Bio:

Professor Sarah Berry is a nutritional scientist at King’s College London and the Chief Scientist at ZOE, where she leads research on personalised nutrition, metabolic health, and the gut microbiome. She is one of the lead scientists behind the PREDICT studies — the world’s largest programme looking at individual responses to food — and has authored more than 200 peer-reviewed publications. Sarah is a leading communicator on evidence-based nutrition and co-hosts the ZOE Science & Nutrition podcast.

📚 Recommended Reading & Resources

● ZOE personalised nutrition programme – https://joinzoe.com

● PREDICT 1 study – https://www.nature.com/articles/s41591-020-0934-0

● Professor Sarah Berry (King’s College London profile) – https://www.kcl.ac.uk/people/sarah-berry

● ZOE Science & Nutrition podcast – https://zoe.com/learn/podcast

● Tim Spector’s work on the microbiome – https://www.tim-spector.co.uk

● Ultra-processed foods overview (WHO) – https://www.foodnavigator.com/Article/2025/06/19/who-ultra-processed-food-guidance/

● Our World in Data: Diet & Obesity – https://ourworldindata.org/diet-compositions

● Meta-analysis on glycaemic variability & health – https://pubmed.ncbi.nlm.nih.gov/31220802

● The Nurses Health Study – https://nurseshealthstudy.org/

● Gut microbiome science summary (Microbiome Journal) – https://microbiomejournal.biomedcentral.com

💬 Quote Highlights:

“There is no perfect diet — there is only the best diet for you.” — Sarah Berry

 “Two people eating the same muffin can have completely opposite metabolic responses.” — Sarah Berry

“We’ve been telling people what to eat for decades. It hasn’t worked. We need a new approach.” — Sarah Berry

“Ultra-processed doesn’t always mean unhealthy — but most of what’s on shelves today definitely is.” — Sarah Berry

“We cannot separate nutrition from sleep, stress, and movement. They’re part of the same system.” — Sarah Berry

🌐 About WePlanet:

WePlanet is a global citizen and science movement challenging bad ideas and championing evidence-based solutions for climate, nature, and human well-being. Learn more at https://www.weplanet.org

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