Dear Lynn:

Is it true that chitosan fiber actually absorbs fat in the body and helps increase weight loss?

Yolanda

Dear Yolanda:

Chitosan is a fiber derived from the exoskeletons of shellfish, insects and other invertebrates. It seems that most of the supply comes from shellfish, as a byproduct of processing.

Quite a few studies have been done on rats and chickens in regards to the fat-absorbing properties of chitosan. It appears that chitosan fiber, which essentially is a water-soluble derivative of cellulose, does absorb up to 10 times its weight in fat. Some studies have also shown that chitosan fiber helps lower total cholesterol levels, by increasing the excretion of cholesterol.

A bit worrisome are other studies that show that in addition to increasing excretion of fat and cholesterol, chitosan fiber also causes increased excretion of several minerals, including calcium, and quite possibly some fat-soluble vitamins such as Vitamin E. It does make sense that as part of dietary fat is made unavailable for absorption, some of the nutritional components associated with that fat are also unavailable.

My recommendation? Right now, there just aren't enough human studies to enable a definitive support of chitosan for either weight loss or cholesterol reduction. If you decide to try chitosan as a weight-loss aid, please do so under the guidance of your physician. Make sure you take a good multivitamin that contains minerals and fat-soluble vitamins at least four hours before or after taking chitosan to help avoid any nutrient deficiencies. Also be aware that if dietary fat is being excreted, you may have gastrointestinal side effects such as gas, bloating, diarrhea or fatty stools.

Sincerely,

Lynn Grieger, R.D., C.D., C.D.E.