Diets
Does intermittent fasting help you lose weight?
The claim, precisely: intermittent fasting decreases body weight
Strong support Diets
RefutedContestedStrong support
consensus score 1.00
Yes, but the benefit comes mostly from eating fewer calories, not the timing itself.
Evidence ladder
How far up the ladder this claim has climbed. A high consensus on a low rung means "consistent so far," not "proven in people."
Top evidence so far: All trials, pooled (Meta-analysis)
MechanismIn-vitroAnimalObservationalRCTMeta-analysis
How the studies fall
3 support 0 contradict 0 tested null 0 mixed · 3 sources, 3 independent groups
What the evidence shows
IF/TRE reduces body weight vs ad libitum eating - well-supported across meta-analyses. (But see the matched-calorie comparison: the benefit is largely 'eating less', not a timing effect.)
The evidence (3)
| Source | Grade | Stance | Quality | Finding |
|---|---|---|---|---|
| (IF SR/MA) 2025 · Sleep Med Rev | meta-analysis | supports | moderate | 18 RCTs: IF lowered weight/BMI/fat/waist vs ad libitum ⚠️ correction-on-file (Crossref) - kept, corrigendum not retraction |
| (BMJ network MA) 2025 · BMJ | meta-analysis | supports | moderate | Network MA: IF variants lower weight vs ad libitum; ~equivalent to continuous calorie restriction head-to-head |
| (IF body-comp SR/MA) 2025 · Nutr J | meta-analysis | supports | moderate | IF improved body composition & cardiometabolic vs control |
Educational only, not medical advice. Grades and scores reflect published evidence weighted by study design and quality; see the methodology.