Chitosan is frequently marketed as a form of natural weight loss supplement. It is found in products where it is the only active ingredient as well as in formulations with several ingredients. It is a substance that is made out of crustacean shells, from creatures such as lobster, crab, and shrimp. The majority of product manufacturers that use this substance as a part of their diet pills claim that this ingredient helps to combat the absorption of fat into the body. However, there is very little clinical evidence that supports this claim or that chitosan has any other weight loss benefits, for that matter.
In 2008, a report was published in the Cochrane Database of Systematic Reviews, which detailed the review that researchers conducted regarding 15 different clinical trials. This represented the participation of a total of 1,219 people in test of the effects of chitosan on overweight and obese adults. When compared to the results achieved by the participants who were given placebos, those who were treated with chitosan, those in the second group appeared to have experienced positive changes in blood pressure, cholesterol levels, and weight loss.
However, the authors of that review pointed out that the majority of the trials that were reviewed were of a poor quality, at best. Moreover, the results that were generated from high quality studies indicated that the impact of chitosan on weight loss was minimal, at best.
A much broader study was published in 2004 in the American Journal of Clinical Nutrition and it suggested that chitosan may not have any benefit in weight loss. It examined five previously published meta-analyses and reviews which examined a total of 25 different clinical trials. What those authors found was that there was “no evidence beyond a reasonable doubt that any specific dietary supplement is effective for reducing body weight.”
As chitosan has been greatly studied but has yet to produce any evidence that this ingredient works effectively to help to promote weight loss, it is unlikely that many – if any – doctors would recommend the use of this substance on its own or as a part of a formulation in order to help to achieve faster and easier weight loss. This is especially true as the use of this substance comes with the risk of possible adverse reactions such as upset stomach and constipation and it may reduce the body’s ability to absorb certain essential nutrients such as vitamins A, D, E, and K, and calcium.