Supplements
Does white kidney bean "starch blocker" help you lose weight?
The claim, precisely: white kidney bean alpha-amylase inhibitor decreases body weight
Probably yes — a modest 1.6 kg, but it does nothing for blood sugar and is destroyed by baking.
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)
How the studies fall
What the evidence shows
White kidney bean extract (phaseolamin) modestly reduces weight/BMI/fat (MA: -1.62 kg) but is NULL on fasting glucose, insulin and TG — and the active alpha-amylase inhibitor is a heat-labile protein denatured by baking. Only viable as a co-consumed/post-bake standardized extract, never a dough ingredient; near-null on our glycemic endpoints.
The evidence (4)
| Source | Grade | Stance | Quality | Finding |
|---|---|---|---|---|
| Onakpoya 2011 · Br J Nutr | meta-analysis | contradicts | moderate | MA: P. vulgaris extract gave non-significant weight loss vs placebo; poor-quality RCTs limit conclusions |
| Payab 2020 · Phytother Res | meta-analysis | supports | moderate | MA: P. vulgaris significantly improved weight (SMD -0.88) in overweight/obese adults |
| Jager 2024 · Sci Rep | RCT | supports | moderate | 12-wk Phase2 white kidney bean extract dose-dependently reduced body weight, fat mass, BMI vs placebo |
| (white kidney bean MA, 8 RCTs) 2026 · (SR/MA) | meta-analysis | supports | moderate | MA 8 RCTs n=543: weight -1.62 kg, fat -1.17 kg; glucose/insulin/TG NULL |
Educational only, not medical advice. Grades and scores reflect published evidence weighted by study design and quality; see the methodology.