In addition to various fad diets, you've probably also seen commercials for products like FatBlocker or other drugs that say they block absorption of fat. For the most part these claims tend to be true, but there are side effects to them, most of which are minimized by eating a low-fat diet (although if you were doing that in the first place, you wouldn't need one of these things). One of the side effects is that these drugs will inhibit absorption of the fat soluble vitamins (A,E,K and D). That's why WOW! chips are fortified with these vitamins to offset the increased excretion of them. The second thing is that fat that remains undigested causes proliferation of various bacteria in the lower intenstinal tract which cause gas, bloating, cramps, etc. The best way I've heard of losing wait is drop your caloric intake by 300 calories/day (basically 2 candy bars) until you reach your desired wait. You're not going to turn slim overnight, but it also is less likely to activate your body's starvation response.