Red Grape and Reduced Body Weight

Research synthesisLow evidenceSmall effect3 studies · 1 beneficial · 2 neutral · 0 harmful

Across 3 studies, only 1 (a meta-analysis) reported a small beneficial effect on body weight, while 2 found no significant effect (neutral). The predominant effect size is small across all studies. Median study duration was 56 days (8 weeks), based on one study. The available evidence primarily involves grape seed extract, but dose reporting was limited (only one study used 100 mg/day in adolescents with metabolic syndrome).

Studied populations: obese individuals; adolescents with metabolic syndrome

Caveats: Evidence base is small (only 3 studies) — conclusions should be considered preliminary. Many of the included studies did not reach statistical significance — effect may be smaller than the predominant direction suggests. The beneficial finding came from a broader grape products meta-analysis, whereas two grape-seed-specific analyses showed no effect, suggesting possible heterogeneity by form or context.

Generated Jul 16, 2026

Doses used in studies

mg/day: 100 (median 100, IQR 100–100) — 1 study

Time to effect

Median: 8 weeks · IQR 8 weeks–8 weeks · Range 8 weeks–8 weeks — Reported in 1 of 3 studies

3 of 3 papersPopulation:

Does the Grape Products Intake has an Effect on Body Weight in Adults: A Systematic Review and Meta-analysis of Randomized Controlled Trials.
- 2024-02
- Meta-Analysis · n = 1,284
- Current drug targets 25(2)
- - Mohammad Ali Goudarzi
  - Zahra Sohrabi
  - Mohammad Hashem Hashempur
  - Saeed Nosratabadi
  - Zahra Namkhah
  - Cain C T Clark
  - Neda Haghighat
- PubMed: 38141198
- DOI: 10.2174/0113894501272740231219072525
1 Insight on
- Reduced Body Weight
- High evidence
- Clinical
a greater effect was observed when grape seed extract was used
Effect
Beneficial
Effect size
Small
Significant
Yes
Effect of 8 weeks' supplementation grape seed extract on insulin resistance in iranian adolescents with metabolic syndrome: A randomized controlled trial.
- 2021-01
- RCT · n = 24
- Diabetes & metabolic syndrome 15(1)
- - Alizadeh Mohammad
  - Taghizadeh Shahnaz
  - Kheirouri Sorayya
- PubMed: 33385766
- DOI: 10.1016/j.dsx.2020.12.028
7 Insights on
- Reduced Body Weight
- High evidence
- Clinical
Although changes were observed in other variables, they were not statistically significant
Effect
Neutral
Effect size
Small
Significant
No
Dose
100 mg/day
The effects of grape seed extract on glycemic control, serum lipoproteins, inflammation, and body weight: A systematic review and meta-analysis of randomized controlled trials.
- 2019-12-26
- Meta-Analysis
- Phytotherapy research : PTR 34(2)
- - Omid Asbaghi
  - Behzad Nazarian
  - Željko Reiner
  - Elaheh Amirani
  - Fariba Kolahdooz
  - Maryam Chamani
  - Zatollah Asemi
- PubMed: 31880030
- DOI: 10.1002/ptr.6518
8 Insights on
- Reduced Body Weight
- High evidence
Grape seed did not influence ... anthropometric measurements
Effect
Neutral
Effect size
Small
Significant
No

Red Grape and Reduced Body Weight

Does the Grape Products Intake has an Effect on Body Weight in Adults: A Systematic Review and Meta-analysis of Randomized Controlled Trials.

Effect of 8 weeks' supplementation grape seed extract on insulin resistance in iranian adolescents with metabolic syndrome: A randomized controlled trial.

The effects of grape seed extract on glycemic control, serum lipoproteins, inflammation, and body weight: A systematic review and meta-analysis of randomized controlled trials.