It is not the fats!! Orlistat works in very limited situations. Primarily, it is useful for reducing fat absorption. Therefore, if you have a diet high in fats, it may work. However, in many situations; it is not the fat that makes you fat. As the diet industry has attempted to limit fat, to make foods more palatable, the carb content has increased. So sad, now foods are processed and high in sugars.
See below. Orlistat works by blocking the enzyme that breaks down fats in your diet. This undigested fat then passes out of your body in your bowel movement. Orlistat does not block the absorption of calories from sugar and other non-fat foods, so you still need to restrict your total intake him of high carbohydrate foods and sugars. I've not found it to be of any benefit to my patients.