Summary: New research finds that people who experience larger drops in blood sugar several hours after eating feel hungrier and consume hundreds more calories each day than those with smaller drops.
Source: King’s College London
New evidence shows that steep drops in blood glucose a few hours after a meal are linked to stronger hunger and higher daily calorie intake, helping explain why some people struggle to lose weight even on calorie-controlled diets.
A study published in Nature Metabolism reports results from PREDICT, one of the largest real-world nutrition research programs. The research team, led by scientists at King’s College London and ZOE and including collaborators from Harvard Medical School, Harvard T.H. Chan School of Public Health, Massachusetts General Hospital, the University of Nottingham, Leeds University and Lund University, analyzed how individual metabolic responses to food influence appetite and energy intake.
Researchers collected detailed post-meal blood glucose and health data from 1,070 participants over two weeks, capturing more than 8,000 standardized breakfasts and over 70,000 freely chosen meals. This extensive dataset allowed the team to link individual glucose patterns with hunger ratings and subsequent calorie consumption in everyday settings.
Standardized test breakfasts were provided as muffins matched for calories but varied in macronutrient composition—carbohydrates, protein, fat and fiber. Participants also completed oral glucose tolerance tests to assess how efficiently their bodies process sugar.
Each participant wore a stick-on continuous glucose monitor (CGM) throughout the study to track blood glucose continuously, and a wearable device to record physical activity and sleep. They logged hunger and alertness in a phone app and recorded the timing and content of every meal, enabling precise comparisons between physiological responses and eating behaviour.
Most earlier research focused on the blood glucose rise and fall in the first two hours after eating—the post-meal peak. By contrast, this study highlighted a distinct pattern in some individuals: a rapid decline in glucose 2–4 hours after the initial peak, often dipping below baseline before recovering. The team called this phenomenon a “postprandial glycaemic dip” or “sugar dip.”
Participants who experienced larger sugar dips reported 9% higher hunger ratings and, on average, ate about 30 minutes sooner than those with smaller dips, despite consuming identical meals. In the 3–4 hours after breakfast, big dippers ate roughly 75 more calories, and across the whole day they consumed about 312 extra calories compared with little dippers—an excess that could translate into substantial weight gain over time if maintained.
Dr. Sarah Berry of King’s College London commented that while blood glucose has been suspected to influence appetite, previous studies were inconsistent. This study demonstrates that the size of the glycaemic dip 2–3 hours after a meal predicts hunger and subsequent calorie intake more reliably than the initial glucose peak, shifting how researchers and clinicians should think about post-meal glucose dynamics and appetite control.
Professor Ana Valdes of the University of Nottingham, who led the study team, emphasized the practical importance of the findings: small daily calorie differences add up, and understanding individual blood glucose responses could help people manage appetite and weight more effectively.
Analysis showed wide variation in glucose responses to the same meals between different individuals. The researchers found no clear link between dip size and age, body weight or BMI, although men tended to experience slightly larger dips than women on average. There was also day-to-day variability for the same person, indicating that both stable individual metabolic traits and changing factors such as meal composition and activity influence whether a person experiences a large dip on any given day.
Choosing foods and meal patterns that reduce postprandial glucose dips could help people feel fuller for longer and reduce overall calorie intake. This points toward personalized nutrition strategies—using wearable glucose monitors and individualized guidance—to align diet with each person’s metabolism.
Patrick Wyatt of ZOE, a lead author, noted that wearable technologies like CGMs make it possible to observe each person’s unique responses in real time and to develop data-driven, personalized advice to manage hunger and calorie intake in a way that works with individual biology.
Tim Spector, Professor of Genetic Epidemiology at King’s College London and scientific co-founder of ZOE, concluded that these findings help open the “black box” linking diet and health. The research supports tools that let individuals discover their personal responses to food, helping them choose diets that better support metabolism and gut health.
About this metabolism research news
Source: King’s College London
Contact: Press Office – King’s College London
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Original Research: Closed access. “Postprandial glycaemic dips predict appetite and energy intake in healthy individuals” by Wyatt, P., Berry, S.E., Finlayson, G. et al., Nature Metabolism
Abstract
Postprandial glycaemic dips predict appetite and energy intake in healthy individuals
Understanding how to regulate appetite is essential for effective weight management. This study shows that glucose dips 2–3 hours after a meal predict self-reported hunger and later energy intake better than the initial 0–2 hour glucose peak or incremental area under the glucose curve in that period.
Using continuous glucose monitoring in 1,070 participants from UK and US cohorts, who consumed 8,624 standardized meals and 71,715 ad libitum meals, the authors found that larger average glucose dips at 2–3 hours predicted higher hunger at 2–3 hours, shorter time until the next meal, greater energy intake at 3–4 hours and greater total energy intake at 24 hours. Results were consistent across cohorts and provide a quantitative link between postprandial glycaemia, appetite and energy intake.