The studies on olestra for weight loss are inconclusive. The mechanism behind this appears to be this idea of the compensation effect that most famously with artificial sweeteners. If you give people like, olestra foods and you're just like, here's some foods, people will actually reduce their calory consumption. But if you give them olestra food and you're like, hey,Here's some foods with fewer calories and less fat, they will actually compensate. They know they are eating less at the initial meal with the lestra in it. It seems to be that people don't compensate calories if they don't know that they're eating olestra chips.