The Study
Effects of Time-Restricted Eating (Early and Late) Combined with Energy Restriction vs. Energy Restriction Alone on the Gut Microbiome in Adults with Obesity
This study is like a fair test where people were randomly assigned to eat at different times to see what happens to their gut bacteria. It found that eating earlier in the day changed some good bacteria more than other diets, and those changes were linked to better blood sugar and blood pressure. But it doesn’t prove the bacteria caused the improvements—just that they happened together.
Analysis score
Maximum 90 for a randomized controlled trial.
Where the score came from
Scientists tested if eating all meals between 8am and 4pm helps gut bacteria stay healthy longer than eating later or just eating less.
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 575 / 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.
- 1The changes in bacteria were real but small — not enough to say eating early will definitely improve your health, but it might help more than eating later or just cutting calories.
- 2People who ate early kept more types of good gut bacteria after 6 months; their levels of Faecalibacterium and Subdoligranulum went up, which are linked to lower blood sugar and blood pressure — but the links were small.
Score breakdown, methodology, conflicts of interest, evidence analysis & raw study data
Publication
Journal
Nutrients
Year
2025
Authors
B. Habe, T. Črešnovar, M. Hladnik, Jure Pražnikar, S. Kenig, D. Bandelj, N. Mohorko, A. Petelin, Z. Jenko Pražnikar
Related Content
Claims (6)
Eating all meals within a daily time window improves metabolic function and gut health, even when total calories consumed remain unchanged.
In obese adults, eating only between 8:00 and 16:00 for three months while reducing calorie intake results in increased Faecalibacterium and decreased Bacillota relative to Bacteroidota in the gut microbiome over six months, and these changes are linked to lower fasting glucose levels.
In obese adults, eating within a restricted early window while reducing calorie intake increases the abundance of a gut bacterium called Subdoligranulum, and this increase is weakly linked to lower diastolic blood pressure.
In obese adults, reducing calorie intake alone increases Verrucomicrobiota bacteria during the diet period, while eating all meals within an early window increases Bacteroidota and decreases Bacillota bacteria over time, showing different effects on gut bacteria based on when calories are consumed.
In obese adults, eating within a restricted morning window along with reducing calorie intake maintains or increases gut microbial diversity over six months, whereas reducing calories alone reduces microbial diversity.
In obese adults, eating all meals later in the day while reducing calorie intake leads to a larger decrease in gut microbiome diversity than eating the same meals earlier in the day or reducing calories without changing meal timing.
Not medical advice. For informational purposes only. Always consult a qualified healthcare professional before making health decisions.