Chitosan is a derivative of the shell of marine animals such as crabs and shrimp and, when ingested, results in the formation of a fibrous compound.

Function

Chitosan has an electric charge opposite to that of fats, so theoretically, when ingested with fats, a chemical bond should take place in the digestive tract that makes fats indigestible. The fats bound to the insoluble portion of chitosan should then be excreted with the faeces. The purpose of chitosan supplementation products is thus to reduce the bioavailability of fats, so that the calorie and fat load of the diet is reduced. Unfortunately, however, although the theoretical premises are sound, studies on chitosan have yielded conflicting results. For example, Zahorska-Markiewicz (1995) finds that the intake of chitosan can actually benefit weight loss. In contrast, Mhurchu (2005) found chitosan’s ability to bind to fats and block their absorption to be almost nil. According to this author, one would have to take chitosan for more than a year to lose just one kilo.

Negative notes

As it is a product derived from crustaceans, intake may cause allergy problems in sensitive individuals. It has no side effects in those who are not allergic to shellfish.

Form and dosage

Chitosan products are mostly available on the market in tablet form, but there are also products in powder or tablet form. Research shows that maximum efficacy occurs at dosages between 3 and 6mg/day, about fifteen minutes before meals.