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How to eat sugar without gaining weight (crush your cravings and end energy crashes) | Prof Tim Spector & Prof Sarah Berry

ZOE Science & Nutrition

1h 2m
Transcript

Original podcast

Summary

Written by a model from the transcript; not yet reviewed.

Prof Tim Spector and Prof Sarah Berry explain how sugar affects the body, clarifying that while our cells need glucose to function, we don't need to consume sugar directly—our bodies can produce it from protein, fat, and starch. The key problem isn't sugar itself but the pattern of consumption: modern foods cause rapid glucose spikes followed by an insulin overshoot and a dip below baseline two to four hours later. ZOE research shows that a post-breakfast dip causes people to eat 320 calories more that day. Spector also describes a link between repeated sugar spikes, inflammation traveling via the vagus nerve, and increased risk of Alzheimer's, depression, and other brain disorders.

They distinguish free sugars (added sugar, honey, fruit juices) from intrinsic sugars (sugar within whole foods like fruit), arguing that whole fruit is protective due to fibre and polyphenols that blunt glucose responses. They warn against diet drinks, which maintain sweet cravings without reducing overall calorie intake, and highlight hidden sugars in cereals, yogurts, and sauces. Practical tips include pairing sweets with fats and proteins, taking a 10-minute walk within 30 minutes of eating, and checking labels for sugar content.

  • A post-breakfast glucose dip causes people to consume on average 320 calories more that day, driven by increased hunger and reduced alertness. 18:51
  • The WHO recommends less than 5% of calories from free sugar, but the US averages 15–17% due to widespread use of high fructose corn syrup. 52:20
  • Pairing a high-sugar food with healthy fats and proteins within 30 minutes reduces the glucose peak and prevents the subsequent dip. 54:29
  • A 10-minute walk within 20–30 minutes of eating significantly lowers blood glucose because muscles actively take in circulating glucose. 56:15
  • Switching to diet drinks does not create a calorie deficit because people compensate by eating more of other foods while maintaining their sweet cravings. 48:31

Highlights

  • 14:57

    Hadza Tribe Honey Gorgingstory

    Tim Spector describes spending time with the Hadza hunter-gatherer tribe in East Africa, where the whole tribe would gorge on honey found in a tree for two days, then go weeks without any. He argues this episodic pattern is what we evolved to handle, not daily sugar in every food.

  • 18:10

    The Dip Is the Real Probleminsight

    Sarah Berry argues the real problem with sugar isn't the peak in blood glucose but the subsequent dip below baseline caused by an insulin overshoot. This dip makes people feel tired, hungry, and less alert, driving them to eat more.

  • 18:51

    320 Extra Calories From a Dipdata

    ZOE research found that people who experience a glucose dip after breakfast consume on average 320 calories more that day. Comparing Tim Spector's muesli breakfast to a full-fat yogurt and nuts breakfast, the muesli day led to about 100 extra calories.

  • 21:51

    Sugar, Inflammation, and Brain Diseaseinsight

    Tim Spector explains that the brain uses 25% of our energy and is highly sensitive to glucose fluctuations. Repeated sugar spikes stimulate immune inflammation that travels via the vagus nerve to the brain, linking to conditions from cognitive decline to depression and schizophrenia.

  • 36:17

    Eight Teaspoons in a Candata

    Tim Spector notes that a can of Coca-Cola or Pepsi contains on average around eight teaspoons of sugar. He warns that some iced teas and ginger beers can have even more, and suggests checking the back label knowing roughly four grams equals one teaspoon.

  • 39:52

    Whole Fruit Beats Fruit Juicestrategy

    Sarah Berry pushes back against the social media narrative that fruit is bad because it contains sugar. She explains that whole fruit's fibre and polyphenols blunt the glucose response and counterbalance inflammation, making it fundamentally different from fruit juice or added sugar.

  • 54:13

    How to Eat Cake Safelystrategy

    Sarah Berry's practical advice for enjoying a slice of cake: take a 10-minute walk within 20–30 minutes of eating, or pair the sweet with healthy fats and proteins like full-fat yogurt. Eating dessert within 30 minutes of a main meal also reduces the peak and prevents the dip.

About this episode

How can you enjoy sugar without gaining weight, fuelling cravings or crashing later in the day? The answer, surprisingly, is not to cut it out. In today’s episode, Professor Tim Spector and Professor Sarah Berry discuss which forms of sugar affect your blood sugar levels most, and what small changes you can make today to reduce the impact. They also explore how sharp blood sugar spikes and dips may affect hunger, energy, inflammation and long-term health. By the end of the episode, you’ll know how to spot hidden sugars, how to avoid the afternoon slump and energy crashes, and, most importantly, how to enjoy cake with less impact on your blood sugar. Sugar is not the enemy. But could a few small changes help you enjoy sweet foods without the cycle of cravings, hunger and energy crashes? 🌱 Try our science-backed and tasty wholefood supplement Daily30 🌿Let your gut microbes snack on the ZOE Gut Health Bar Build healthy habits. Download the ZOE app today and start your trial for just £2.30 for your first week. 👉 Join ZOE Follow ZOE on Instagram. Timecodes 00:00 Intro 03:28 If fruit is full of sugar, why is it good for us? 08:30 What really happens after you drink a sugary drink? 12:46 Why sugar leaves you hungry a few hours later 16:15 The blood sugar dip that makes you eat 320 extra calories 19:19 The surprising link between sugar and inflammation 22:00 Can blood sugar affect your brain health? 25:25 What the science really says about sugar and cancer 29:25 We've been blaming sugar for the wrong things 31:45 The 2 types of sugar most people confuse 32:35 The hidden sugars lurking in everyday foods 35:32 Why energy drinks may be worse than you think 38:51 Why orange juice may not be as healthy as you think 40:10 Why fruit and fruit juice are not the same thing 43:53 Why some smoothies behave like sugary drinks 45:03 Should you quit sugar completely? 46:46 Are sweeteners helping or keeping you hooked? 49:55 Is honey actually healthier than sugar? 51:40 3 everyday foods with surprisingly high sugar 52:27 How to enjoy cake without the blood sugar crash 55:01 The 10-minute habit that lowers your glucose response 57:15 Why energy drinks may be making your slump worse 58:32 The biggest sugar traps to watch out for 📚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 Dietary Sugar Intake Associated with a Higher Risk of Dementia, Journal of Alzheimer's Disease (2024) Sugar-Sweetened and Artificially Sweetened Beverages and Risk of Mortality, AHA (2019) A Twin Study of Acne in Women, Journal of Investigative Dermatology (2002) Bananas and weight loss: What does the science say? Food Order and Impact on Glucose and Insulin Levels, Diabetes Care (2015) Here are 4 ways to help manage your blood sugar Whole Fruits Versus 100% Fruit Juice, BNF (2025) Have feedback or a topic you'd like us to cover? Let us know here. Episode transcripts are available here.

Transcript

0:00
1:02:21

11,014 words · 3 speakers

Topics

  • Blood Sugar Management
  • Sugar and Inflammation
  • Metabolic Health
  • Food Labeling
  • Type 2 Diabetes
  • Mental Health and Diet
  • Ultra-Processed Foods
  • Gut Health

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