The Study
1654-P: Effects of Acute Late Isocaloric Eating on 24-h Blood Glycemia in Adults with Overweight and Obesity
This study showed that when people ate their meals later in the day, their blood sugar went up a little more, especially while they were sleeping. But it only tested this for one day in 13 people, so we can't say eating late every night will definitely cause problems.
Analysis score
Maximum 90 for a randomized controlled trial.
Where the score came from
Even if you eat the same food at the same calories, eating dinner late makes your body less able to handle sugar the next morning.
Where does this study sit?
Reviews of RCTs (Meta-analyses)
Max 100Randomized Trials
Max 90Reviews of Cohort Studies
Max 85Cohort Studies
Max 72Reviews of Case-Control Studies
Max 63Case-Control Studies
Max 58Cross-Sectional & Case Series
Max 50Expert Opinion
Max 550 / 100
Quality score
Participants are randomly assigned to treatment or control groups, minimizing bias. The gold standard for testing whether an intervention causes an effect.
Key takeaways
Summary
Based on the study abstract and findings.
- 1Yes — these spikes are similar to early signs of prediabetes and happen even without eating more food.
- 2Blood sugar went up 3% all day, 9% more at night, and the first meal after a long fast caused 87% bigger sugar spikes.
- 3Insulin response dropped 42% right after eating.
Score breakdown, methodology, conflicts of interest, evidence analysis & raw study data
Publication
Journal
Diabetes
Year
2025
Authors
H. Koh, N. Vujović, S. Chellappa, Jingyi Qian, M. Butler, SU WEI HENG, N. Rahman, F. Scheer
Related Content
Claims (6)
When people eat all their daily calories earlier in the day instead of later, and consume the same total number of calories, their fasting blood sugar and diastolic blood pressure are lower.
In adults with overweight or obesity, eating the same amount of food later in the day raises blood glucose levels by 3% over 24 hours compared to eating the same food earlier, with an additional 9% higher rise during sleep, showing that the timing of meals affects blood glucose independently of total calories or nutrients.
In adults with overweight or obesity, eating the first meal of the day after a 20-hour fast causes a 42% reduction in the initial insulin spike after eating, while total insulin released over three hours remains unchanged, showing a temporary decrease in how strongly pancreatic beta cells respond to glucose.
In adults with overweight or obesity, fasting for 20 hours before the first meal leads to an 87% larger spike in blood glucose after eating compared to fasting for 16 hours.
In adults with overweight or obesity, eating later in the day does not change total insulin exposure over 24 hours but lowers insulin levels during daytime hours by 5%, showing that glucose and insulin patterns change independently, which is linked to differences in how insulin is released or how tissues respond to it.
In adults with overweight or obesity, eating late at night causes a 9% higher blood glucose level during sleep, and the body's internal clock worsens this effect during rest.
Not medical advice. For informational purposes only. Always consult a qualified healthcare professional before making health decisions.