from what i hear is if you eat more than 15 grams of fat in one meal you may have an accident in your pants...My sister was on alli and thought she farted and actually had an accident. I started alli 4 days ago with no side effects at all...i have been eating very low fat foods. I am scared to have an accident so i try to stay below 9 grams of fat for each meal...Let me know how it goes...