MAASTRICHT, Netherlands—A green tea–caffeine mixture as well as a high-protein diet, improved weight maintenance independently through thermogenesis, fat oxidation, sparing fat-free mass and satiety (for the high-protein diet) but a possible synergistic effect between the two did not appear (Am J Clin Nutr. 2009;89:822-30).
The randomized, placebo-controlled, double blind, parallel trial was conducted in 80 overweight and moderately obese subjects matched for sex, age, body mass index (BMI), height, body mass and with a habitually low-caffeine intake. A very-low-energy diet intervention during week four was followed by three months of weight maintenance (WM); during the WM period, the subjects received a green tea–caffeine mixture (270 mg/d epigallocatechin gallate (EGCG) + 150 mg caffeine/d) or a placebo, both in addition to an adequate-protein (AP) diet (50 to 60 g/d of protein) or a high-protein (HP) diet (100 to 120 g/d of protein).
Subjects lost 7.0 ± 1.6 kg or 8.2 ± 2.0 percent body weight (P<0.001). During the WM phase, WM, resting energy expenditure, and fat-free mass (FFM) increased relatively in both the HP groups and in the AP + green tea–caffeine mixture group (P<0.05), whereas respiratory quotient and body fat mass decreased, all compared with the AP + placebo group. Satiety increased only in both HP groups (P<0.05). The green tea–caffeine mixture was only effective with the AP diet.
