Body fat loss achieved by stimulation of thermogenesis by a combination of bioactive food ingredients: a placebo-controlled, double-blind 8-week intervention in obese subjects.

Author: Belza A, Frandsen E, Kondrup J

Author affiliation: Department of Human Nutrition, Centre for Advanced Food Studies, The Royal Veterinary and Agricultural University, Frederiksberg C, Denmark. anbe@kvl.dk

Publication date & source: 2007.01, Int J Obes (Lond)., 31(1):121-30. Epub 2006 Apr 25.

Publication type: Research Support, Non-U.S. Gov't

BACKGROUND: A combination of tyrosine, capsaicin, catechines and caffeine may stimulate the sympathetic nervous system and promote satiety, lipolysis and thermogenesis. In addition, dietary calcium may increase fecal fat excretion. OBJECTIVE: To investigate the acute and subchronic effect of a supplement containing the above mentioned agents or placebo taken t.i.d on thermogenesis, body fat loss and fecal fat excretion. DESIGN: In total, 80 overweight-obese subjects ((body mass index) 31.2+/-2.5 kg/m(2), mean+/-s.d.) underwent an initial 4-week hypocaloric diet (3.4 MJ/day). Those who lost>4% body weight were instructed to consume a hypocaloric diet (-1.3 MJ/day) and were randomized to receive either placebo (n=23) or bioactive supplement (n=57) in a double-blind, 8-week intervention. The thermogenic effect of the compound was tested at the first and last day of intervention, and blood pressure, heart rate, body weight and composition were assessed. RESULTS: Weight loss during the induction phase was 6.8+/-1.9 kg. At the first exposure the thermogenic effect of the bioactive supplement exceeded that of placebo by 87.3 kJ/4 h (95%CI: 50.9;123.7, P=0.005) and after 8 weeks this effect was sustained (85.5 kJ/4 h (47.6;123.4), P=0.03). Body fat mass decreased more in the supplement group by 0.9 kg (0.5; 1.3) compared with placebo (P<0.05). The bioactive supplement had no effect on fecal fat excretion, blood pressure or heart rate. CONCLUSION: The bioactive supplement increased 4-h thermogenesis by 90 kJ more than placebo, and the effect was maintained after 8 weeks and accompanied by a slight reduction in fat mass. These bioactive components may support weight maintenance after a hypocaloric diet.