Diets
Is keto better than low-fat for losing weight?
The claim, precisely: ketogenic diet decreases body weight
Leans support Diets 🔬 Includes disconfirming
RefutedContestedStrong support
consensus score 0.29
Probably yes for short-term loss, but it is not superior once calories and protein are matched.
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
1 support 0 contradict 2 tested null 0 mixed · 3 sources, 1 independent group
What the evidence shows
Carbohydrate restriction does NOT beat low-fat for weight when diet quality/protein/calories are accounted for - the 'carbohydrate-insulin / metabolic-advantage' framing is unsupported. (Keto does cause real short-term weight loss vs baseline; it just isn't superior.)
The evidence (3)
| Source | Grade | Stance | Quality | Finding |
|---|---|---|---|---|
| Hu T, et al. (Bazzano) 2012 · Am J Epidemiol | meta-analysis | tested-null | high | MA 23 RCTs n=2788: weight/waist reductions NOT significantly different LCD vs LFD |
| Gardner CD, et al. (DIETFITS) 2018 · JAMA | RCT | tested-null | high | RCT n=609 12mo: healthy-LC -5.3kg vs healthy-LF -6.0kg, NS; insulin-secretion 'responder' hypothesis failed |
| Bueno 2013 · Br J Nutr | meta-analysis | supports | moderate | MA of 13 RCTs >=12mo: VLCKD gave modestly greater long-term weight loss (~0.9 kg) than low-fat |
Educational only, not medical advice. Grades and scores reflect published evidence weighted by study design and quality; see the methodology.