Over the last few years so-called fat trappers came to the forefront in the weight-loss industry. The manufacturers of these products usually claim that you can keep on eating as before, just pop a pill afterwards to bind (”trap”) the fat and you’ll lose weight easily. And to be honest, isn’t that what we all wish for? To eat as much as we want of what we want as many times as we want without living with the effects of this indiscipline.
The active ingredient in these products usually is chitosan, a compound derived from shellfish. Chitosan is a form of fiber which, like other forms of fiber, such as oat bran, is not well digested by the human body. As it passes through the digestive tract, it seems to have the ability to bond with ingested fat and carry it out in the stool. It is this aspect which some (dare I say dubious) manufacturing companies cling to in order to promote their products as the next big weight-loss cure. The scientific evidence though is not very positive. The biggest study to date included 250 obese people who were given 3 gram (quite high) of chitosan per day. This high dosage failed to increase weight-loss as compared to the placebo group, meaning that it is not effective at all.
But that’s not all. There is substantial evidence that those of us who use high doses of chitosan over long periods might make it difficult for our bodies to absorb minerals like calcium, magnesium, selenium and even some vitamins (A, D and E). There are several risks to having low levels of calcium and the other minerals, one of which is an increased risk of osteoporosis. Some concerned scientists also mention that long-term ingestion of chitosan could change the balance of the intestinal flora and allow the growth of unhealthful bacteria. Lastly, it is also necessary to mention that shellfish can concentrate arsenic in their shells. This of course means that the product that you are using right now might include arsenic as a rather “unwanted” byproduct.
