Introduction
Chitosan, a partially deacetylated polymer of N-acetyl
glucosamine derived from the polysaccharide chitin, appears
to bind to negatively charged lipids in animal trials, hence
reducing their gastrointestinal uptake1–3 and lowering serum
cholesterol.4,5 Some human trials have suggested that chitosan
may decrease body weight and serum lipids,6,7 and a metaanalysis
8 suggested a 3.3 kg greater weight loss in the
intervention group compared with placebo. Other studies
have found no effect of chitosan on clinical outcomes.9,10 In
order to resolve the uncertainty surrounding the effectiveness
of this dietary supplement,11,12 we conducted a large
randomised controlled clinical trial of the effect of chitosan
on body weight, lipids, and other health outcomes.