Harvard Doctor: Obesity, cancer, and the real cost of convenience food | Dr. Andy Chan

Ultra-processed foods now make up over half of what many of us eat - and the health consequences are only just coming into focus. In this episode, we reveal what’s really happening inside your body when you eat these foods daily.

Our guest is Dr. Andy Chan, a Harvard professor and leading expert on gut health and cancer prevention. He heads the Clinical and Translational Epidemiology Unit at Massachusetts General Hospital and has published over 400 scientific papers.

Dr. Chan breaks down the hidden links between UPFs, inflammation, and diseases like obesity, diabetes, and colorectal cancer. You’ll hear why some foods that look healthy on the shelf may be doing long-term damage - and how the gut microbiome plays a crucial role in the process.

This is the research big food companies don’t want you to hear. If you care about what you and your family are eating, don’t miss this conversation.

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Timecodes

00:00How much of our food is ultra-processed?

02:24Can UPFs increase cancer risk in children?

04:48Why our kids get sicker, earlier

07:12How convenience took over our food choices

09:36Are food companies engineering addiction?

12:00UPFs and early onset cancer

14:24Why calorie counting misses the point

16:48Can a mother’s diet shape her child’s future health?

21:36Is a poor diet as harmful as smoking in pregnancy?

26:24Preservatives vs calories: what’s more harmful?

28:48Brand new science: not all UPFs are equal

31:12ZOE’s new processed food risk scale

38:24Why UPF labels are misleading and confusing

40:48A simple trick: how to spot UPFs on food labels

43:12Should schools and offices be UPF-free zones?

45:36How to shape your kids’ eating habits for life

📚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

Free resources from ZOE

Live Healthier: Top 10 Tips From ZOE Science & Nutrition

Gut Guide - For a Healthier Microbiome in Weeks

Mentioned in today's episode

Trendsin Adults’ Intake of Un-processed/Minimally Processed, and Ultra-processed foods at Home and Away from Home in the United States from 2003–2018,2025,The Journal of Nutrition

Ultra-processedfood intake in toddlerhood and mid-childhood in the UK: cross sectional and longitudinal perspectives, 2024,European Journal of Nutrition

TheHealthfulness of the US Packaged Food and Beverage Supply: A Cross-Sectional Study, 2019,Nutrients

UltraprocessedFood Consumption and Cardiometabolic Risk Factors in Children, 2024,JAMA Network Open

Maternalconsumption of ultra-processed foods and subsequent risk of offspring overweight or obesity: results from three prospective cohort studies, 2022,British Medical Journal

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Episode transcripts are available here.