Effects of dietary supplementation with epigallocatechin-3-gallate on weight loss, energy homeostasis, cardiometabolic risk factors and liver function in obese women: randomised, double-blind, placebo-controlled clinical trial

Randomized, double-blind, placebo-controlled trial in obese premenopausal Caucasian women from Vitoria-Gasteiz, Spain. Participants were 19-49 years old, had BMI 30.0-39.9 kg/m2, and were non-diabetic and without major liver or renal disease; all followed a supervised 12-week energy-restricted diet.

Epigallocatechin-3-gallate (EGCG) was given orally as green tea extract TEAVIGO TM at 300 mg/day, divided into three doses with breakfast, lunch, and dinner for 12 weeks. The comparison was placebo containing 300 mg lactose/day.

EGCG did not add benefit to the energy-restricted diet. Compared with placebo, there were no significant differences in changes in body weight, BMI, fat mass, lean mass, waist circumference, resting metabolic rate, glucose, insulin, HOMA-IR, lipids, CRP, or liver enzymes after 12 weeks. The supplement was well tolerated, and no participants withdrew because of discomfort or adverse effects; no adverse effects on liver biomarkers were seen. The active group randomized 43 participants and 39 were analyzed at follow-up, versus 40 randomized and 39 analyzed in the placebo group.

The trial was relatively small, with only 39 analyzed participants in the EGCG group and 39 in placebo, which limits power to detect modest effects. Duration was short at 12 weeks, and results apply mainly to obese premenopausal Caucasian women from a single Spanish center receiving an energy-restricted diet, limiting generalizability.