Chitosan supplementation and fecal fat excretion in men.
OBJECTIVE
Few weight loss supplements are clinically tested for efficacy, yet their proliferation continues. Chitosan-based supplements are sold as fat trappers and fat magnets. They purportedly block fat absorption and cause weight loss without food restriction. We quantified the in vivo effect of a chitosan product on fat absorption.


METHODS
Participants (n = 15) consumed five meals per day for 12 days. Energy intake was not restricted. Participants consumed no supplements during a 4-day control period and two capsules five times per day (4.5 g chitosan/d), 30 minutes before each meal, during a 4-day supplement period. All feces were collected from days 2 to 12. Oral charcoal markers permitted division of the feces into two periods. The two fecal pools were analyzed for fat content.


RESULTS
Participants were male, 26.3 +/- 5.9 years old, BMI of 25.6 +/- 2.3 kg/m(2). Subjects consumed 133 +/- 23 g of fat/d and 12.91 +/- 1.79 MJ/d (3084 +/- 427 kcal/d). Individual meals averaged 26.3 +/- 9.3 g of fat. With chitosan supplementation at 10 capsules/day, fecal fat excretion increased by 1.1 +/- 1.8 g/d (p = 0.02), from 6.1 +/- 1.2 to 7.2 +/- 1.8 g/d.


CONCLUSIONS
The effect of chitosan on fat absorption is clinically negligible. Far from being a fat trapper, at 0.11 +/- 0.18 g of fat trapped per 0.45-g capsule or 1.1 g (9.9 kcal) fat trapped per day, this product would have no significant effect on energy balance. The fat trapping claims associated with chitosan are unsubstantiated.
Department of Nutrition and. Department of Internal Medicine, University of California Davis, Davis, California 95616, USA.
Matthew D
MD
Gades
Judith S
JS
Stern
D000328:Adult; D019440:Anti-Obesity Agents / Q000494:pharmacology*; D002686:Chitin / Q000031:analogs & derivatives* / Q000494:pharmacology*; D048271:Chitosan; D015930:Diet Records; D004041:Dietary Fats / Q000378:metabolism*; D019587:Dietary Supplements; D005243:Feces / Q000737:chemistry; D006801:Humans; D007408:Intestinal Absorption / Q000187:drug effects; D008297:Male; D015431:Weight Loss
D019440:Anti-Obesity Agents; D004041:Dietary Fats; D002686:Chitin; D048271:Chitosan