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.
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.


METHODS
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.


CONCLUSIONS
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.
Belza
A
A
Department of Human Nutrition, Centre for Advanced Food Studies, The Royal Veterinary and Agricultural University, Frederiksberg C, Denmark. anbe@kvl.dk
Frandsen
E
E
Kondrup
J
J
D000273:Adipose Tissue / Q000187:drug effects*; D019440:Anti-Obesity Agents / Q000008:administration & dosage*; D001823:Body Composition / Q000187:drug effects; D001835:Body Weight / Q000187:drug effects; D002110:Caffeine / Q000008:administration & dosage; D002136:Calcium, Dietary / Q000652:urine; D028241:Camellia sinensis; D002211:Capsaicin / Q000008:administration & dosage; D002392:Catechin / Q000008:administration & dosage; D004041:Dietary Fats / Q000008:administration & dosage / Q000032:analysis; D019587:Dietary Supplements; D004311:Double-Blind Method; D004734:Energy Metabolism / Q000502:physiology; D005243:Feces / Q000737:chemistry; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009765:Obesity / Q000178:diet therapy*; D010936:Plant Extracts / Q000008:administration & dosage; D022722:Thermogenesis / Q000187:drug effects*; D014443:Tyrosine / Q000008:administration & dosage; D015431:Weight Loss / Q000187:drug effects
D019440:Anti-Obesity Agents; D002136:Calcium, Dietary; D004041:Dietary Fats; D010936:Plant Extracts; D002110:Caffeine; D014443:Tyrosine; D002392:Catechin; D002211:Capsaicin