Green Tea Leaf Extract (EGCG) For Weight Loss
EGCG is the most potent molecule in green tea.
As far as research goes, there’s been several studies looking into how supplementing with green tea extract can impact fat-loss and fat-oxidation.
Let’s breakdown some of the key ones.
Fat Loss Studies:
- In one study, subjects were divided into 4 groups and given various doses of catechin enriched green tea. The group receiving the highest dose of catechins were found to have a decrease in waist and total weight loss of 1.2 kg in 90 days relative to control (1). The subjects receiving a medium dosage also lost weight relative to control, but the extent of results was found to be related to the dose.
- In another study, half the participants were given 625mg of catechins induced with 39mg of caffeine while the other half were given just 39mg of caffeine. After 12-weeks, both groups lost about the same amount of fat-mass but the group receiving catechins seemed to lose more abdominal fat (2).
- In a meta-analysis of 11 studies that looked at the effects of green tea extract supplementation over a minimum time of 12-weeks, researchers concluded that subjects experience, on average, 1.31kg of weight-loss (3).
Based on the research, there does seem to be some correlation between green tea extract supplementation and fat-loss.
However, this correlation is not significant.
To be clear:
Fat oxidation is referring to the percentage of energy expenditure coming from fat rather than glucose.
- Obese men supplementing with 300mg (but not 600mg) of ECGC supplementation were found to have increased fat-oxidation (4).
- Elite male cyclists were given either 270mg of EGCG, placebo, or caffeine at 3mg/kg of bodyweight. EGCG did not increase fat-oxidation but caffeine did (5).
- In a meta-analysis of green tea consumption, researchers report that a cup of green tea is likely to cause approximately 5.7g of body fat to be ‘burnt’ (6).
Based on the research, there does seem to be a slight (but unreliable) correlation between EGCG intake and fat-oxidation.