Chitosan supplementation and fecal fat excretion in men

Matthew D. Gades, Judith S. Stern

Research output: Contribution to journalArticlepeer-review

96 Scopus citations


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. Research Methods and Procedures: 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/m2. 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 ± 71.8 g/d (p = 0.02), from 6.1 ± 1.2 to 7.2 ± 1.8 g/d. Discussion: 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.

Original languageEnglish (US)
Pages (from-to)683-688
Number of pages6
JournalObesity Research
Issue number5
StatePublished - 2003


  • Chitosan
  • Dietary fiber
  • Fat absorption
  • Obesity
  • Supplements

ASJC Scopus subject areas

  • Medicine (miscellaneous)
  • Public Health, Environmental and Occupational Health
  • Endocrinology
  • Food Science
  • Endocrinology, Diabetes and Metabolism


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