The evolutionary science behind why you can’t lose weight and how to avoid 5 modern food mistakes | Prof Daniel Lieberman

Why can’t you lose weight, and why do modern diets fail?

Today, Harvard professor Daniel Lieberman explains how evolution shapes hunger, body fat, food cravings, and modern food mistakes. You will learn why eating well can feel so hard in today’s food world.

Using themes from Daniel’s new book, Fed Up: What Evolution Reveals about Food, Diet and Eating Well, we explore how our modern food environment explains weight gain, failed diets, and confusion about what to eat. We discuss calorie counting, ultra-processed food, hunger, and why there may be no single “best” diet for everyone.

By the end of the episode, you’ll have some simple ways to make better food choices and will know how to make healthy choices easier.

If your body evolved for a world where food was scarce, what does that mean for how you eat today?

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Timecodes

00:00 Intro

03:34 The 3 reasons evolution changes what you eat

07:28 Why supermarkets make healthy eating harder

10:51 Why sugar and fat are so hard to resist

12:12 Are humans really fatter than hippos?

13:20 Why your brain burns so much energy

14:25 Why humans evolved to hold onto fat

16:06 The 3 hidden costs behind body fat

18:23 How cooking changed the human body

19:15 Why raw food may not be natural for humans

22:08 Did farming make humans less healthy?

24:49 How processed food transformed what we eat

28:22 Why modern food triggers ancient cravings

29:48 What the paleo diet gets wrong

31:08 Why there is no real paleo diet

31:55 Why calorie counting can mislead you

33:05 Why hunger beats willpower

34:20 Why weight loss often comes back

35:56 What you need to know before buying food

36:53 Why no diet is truly optimal

38:24 What the healthiest diets have in common

40:08 Are your genes really making you gain weight?

41:40 The simple shopping trick Daniel uses

43:46 Why the 8-hour sleep rule is wrong

45:25 Why stress makes you crave comfort food

51:30 Why simple diet rules fail

📚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

Fed Up: What Evolution Reveals about Food, Diet and Eating Well by Daniel Lieberman

Comparing dietary variation between tropical hunter-gatherer groups to the Paleo Diet, The American Journal of Clinical Nutrition (2023)

The carbohydrate-insulin model: a physiological perspective on the obesity pandemic, The American Journal of Clinical Nutrition (2021)

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Episode transcripts are available here.