How Efficient Is Fat Digestion and Can We Decrease Fat Absorption?

The efficiency of the digestion and absorption of the fat and cholesterol we eat is greater than 90 percent. Certain drugs and dietary supplements have been marketed to reduce the absorption of fat from the diet. For instance, the supplement chitosan is fiber-like substance derived from chitin. Chitin is a polysaccharide-like structure made up of amino sugars (sugars with nitrogen) which helps harden the shells of shellfish (shrimp, lobster, crab), insects (beetles), and is also found in some other animals and the cell walls of some fungi. Chitosan is a processed form of chitin

and it is used in the food and drug industry and in supplements. Chitosan is more water soluble than chitin and is often marketed as a fat binder in the digestive tract.

In addition the drug xenical (Orlistat) hinders the actions of pancreatic lipase, the principal fat-digesting enzyme. This results in less absorption of diet-derived fat and more fat in the feces. Orlistat has been shown in research studies to be an effective therapy for weight loss and is recommended in conjunction with a healthy, reduced calorie and fat diet and exercise program. Because Orlistat can increase the amount of fat in the lower digestive tract there is the potential for side effects such as loose, oily stools and flatulence. Furthermore, because there is the possibility of reduced absorption of fat-soluble vitamins, manufacturers recommend the use of a supplement at least 2 hours before the use of Orlistat.