Green tea extract effects on body weight, hormones and oxidative stress in people
What it found
Taking green tea extract lowered body weight, body fat percentage, BMI and a marker of oxidative stress in adults.
It also raised levels of adiponectin and total antioxidant capacity.
What they found
Studies in people
Body weight and BMI
Across the trials, taking green tea extract led to small but significant drops in body weight and BMI. However, it did not change waist size or overall fat mass when all studies were combined.
Body fat percentage
People who took green tea extract saw a small drop in their body fat percentage compared with those who did not take it.
Oxidative stress markers
Green tea extract lowered malondialdehyde, a sign of oxidative damage in the body. It also raised total antioxidant capacity, meaning the body had more ability to handle oxidative stress.
Hormones related to obesity
Levels of adiponectin, a hormone involved in how the body handles sugar, went up after taking green tea extract. Two other hormones, leptin and ghrelin, did not change.
Doses used in trials
The studies tested green tea extract at amounts between 60 and 3000 mg per day. Some benefits were seen only at certain doses or in specific groups like men or younger adults.
What the authors conclude
- They suggest that green tea extract can lower body weight, BMI, body fat percentage and oxidative stress in adults.
- They note that it may work as a dietary supplement to raise total antioxidant capacity and adiponectin levels.
How it was done
Obesity is linked to higher oxidative stress and changes in hormones that control appetite and metabolism. Earlier studies gave mixed results about whether green tea extract could help with these issues.
The authors gathered 59 randomised controlled trials involving 3802 adult participants. The trials lasted between 2 and 48 weeks, using daily doses of green tea extract ranging from 60 to 3000 mg.
What it can’t tell you
- These trials looked at concentrated green tea extract supplements, so the results may not match what happens from drinking regular brewed tea.
- Because the trials lasted up to 48 weeks, scientists do not yet know if these effects continue over many years.
Who paid
- Authors work at
- Shahid Beheshti University of Medical Sciences, Iran; Isfahan University of Medical Sciences, Iran; Ahvaz Jundishapur University of Medical Sciences, Iran
The paper
- Title
- The effects of green tea extract supplementation on body composition, obesity-related hormones and oxidative stress markers: a grade-assessed systematic review and dose-response meta-analysis of randomised controlled trials
- Type
- Systematic review and meta-analysisThe authors follow a set, published method to find every relevant study, then combine the numbers from them into one result.
- Evidence
- Studies in people
- Summarised from
- Full text
- Cite
- Asbaghi O, Rezaei Kelishadi M, Larky DA, et al (2024). The effects of green tea extract supplementation on body composition, obesity-related hormones and oxidative stress markers: a grade-assessed systematic review and dose-response meta-analysis of randomised controlled trials. The British journal of nutrition. doi:10.1017/S000711452300260XFree full textPubMed 38031409DOI
Summary written 1 Oct 2026. Check it against the paper before it changes what you eat. How we summarise papers · Report an error