Often we see the term "low-fat" or "nonfat" on a product, and it triggers something in our brains to think that we can eat more of the item because, after all, it's low-fat. Just keep in mind that it's very possible to end up eating more calories by eating a lot of the low-fat food rather than just eating a small amount of the full-fat food. This happened to me when Snackwells came out. Remember those? They were the first mass-marketed low-fat cookie on the market, and I was gobbling them up, literally.
I'm not saying you should stop eating low-fat, but remember that a bag of cookies labeled as low-fat does not give you the green light to eat the whole bag. Personally, I'd rather have one really good full-fat cookie and be done with it.
Have you ever overindulged on something because it was low-fat or nonfat?