We assessed the effect of ingestion of green tea (GT extract along with a low-energy diet (LED)on resting energy expenditure (REE), substrate oxidation and body weight as GT has been shown to increase energy expenditure and fat oxidation in the short tenm in both animals and people. Forty-six overweight women (BMI 27.6 (sD 1.8) kg/m2) were fed in energy balance from day 1 to day 3, followed by a LED with GT (1125 mg tea catechins +225 mg caffeineld) o placebo (PLAC) from day 4 to day 87. Caffeine intake was standardised to 300mg/d. Energy expenditure was measured on days 4 and 32. Reductions in weight (4.19 (sD 2-0) kg PLAC, 4.21 (sD 2-7) kg GT), BMI. waist hip ratio, fat mass and fat-free mass were not statistically different between treatments. REE as a function of fat-free mass and fat mass was significantly reduced over 32 d in the PLAC group (P