Researchers at the University of California-Davis have demonstrated that chitosan fat blocker products do not significantly block absorption of dietary fat.

Chitosan is derived from chitin, a polysaccharide found in the exoskeleton of shellfish such as shrimp, lobster, and or crabs. Many sellers claim that chitosan causes weight loss by binding fats in the stomach and preventing them from being digested and absorbed. Some refer to it as a "fat magnet" or "fat trapper."

The study involved 15 men who consumed five meals per day for 12 days with a daily total of about 25 grams of fat per meal. The amount of fat excreted during four days when they took chitosan supplements was then compared to the amount excreted during days without chitosan. Taking 10 capsules of chitosan per day increased fecal fat excretion by only about 1 gram (9 calories), which would have no significant effect on a person's weight.

1) Gades M, Stern JS. Chitosan supplementation and fecal fat excretion in men. Obesity Research 11:683-688, 2003.

At least three previously published studies have had similar findings: 2) Pitler MH and others. Randomized, double-blind trial of chitosan for body weight reduction. European Journal of Clinical Nutrition 53:379-381, 1999.

3) Wuolijoki E and others. Decrease in serum LDL cholesterol with microcrystalline chitosan. Methods and Findings in Experimental and Clinical Pharmacology 21(5):357-361, 1999.

4) Ho SC and others. In the absence of dietary surveillance, chitosan does not reduce plasma lipids or obesity in hypercholesterolaemic obese Asian subjects. Singapore Medical Journal 42:6-10 , 2001.

Checked 5/3/07

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