The truth about low carb diets, sugar spikes, and ‘multigrain’ labels | Prof. Tim Spector

Carbs are one of the most misunderstood aspects of nutrition. For decades, they’ve been praised, demonized, and debated. Today, low-carb diets are everywhere, but the reality is more nuanced. While over 80% of the carbs we eat come from low-quality, refined sources, the right kinds of carbs are essential for good health. In this episode, Professor Tim Spector breaks down the difference between good and bad carbs and explains why quality matters more than quantity. He explores how the rise of ultra-processed foods has led to an overconsumption of unhealthy carbohydrates, contributing to energy crashes, hunger, and long-term health issues. He also explains the benefits of fiber-rich carbs, their role in gut health, and why cutting carbs entirely may not be the best approach. The episode also answers common questions about carbs, including the best time to eat them, how to pair them for better digestion, and whether alternatives like almond flour are actually healthier. Tim also shares practical tips, such as why freezing bread might be a simple way to make it better for you. 🥑 Make smarter food choices. Become a member at zoe.com - 10% off with code PODCAST 🌱 Try our new plant based wholefood supplement - Daily 30+ Follow ZOE on Instagram . Timecodes: 00:00 Introduction 01:39 Quickfire questions 03:06 What is a carb? 07:43 Is rice healthy? 08:56 What makes sugars unhealthy? 11:49 Truth about sugar spikes 14:49 Potatoes, white rice, bread and pasta 18:44 'Big Food' industry 21:22 What is a good carb? 27:32 Effects of low carb diets 33:18 Effects on mood & energy 36:25 Tim's favourite carbs 39:48 When should you eat carbs? 41:47 Eating carbs with other foods 46:45 Should you freeze bread? 50:33 The healthiest rice 50:53 Is multigrain and wholemeal healthy? 56:20 Should you consume flour? 59:45 Easy way to improve healthy carb intake 📚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 Trends in Dietary Carbohydrate, Protein, and Fat Intake and Diet Quality Among US Adults, 1999-2016 , 2019, published in Journal of the American Medical Association Carbohydrate intake for adults and children: WHO guideline , 2023, published by World Health Organization Association between changes in carbohydrate intake and long term weight changes: prospective cohort study , 2023, published in British Medical Journal Low-Carbohydrate Diet , 2023, published in National Library of Medicine Diet Review: Ketogenic Diet for Weight Loss , published by The Nutrition Source, Harvard TH Chan School of Public Health Have feedback or a topic you'd like us to cover? Let us know here . Episode transcripts are available here .