Originally Posted by Banana Brain
That actually isn't true, there are no "negative" calorie foods, not even celery or lettuce (unless you REALLY really chewed). The only food garenteed negative calories would be cardboard- its 100% fiber.
Actually...it is true - at least for celery. (sorry to be like this in my first few posts)
While there are calories in celery, your body uses more digesting it (not chewing, but digesting) than you consume by ingesting it. You'd have to tonnes of it over a year to make any significant difference, though.
Unfortunately, most of the rest of that list is not, in fact, "negative calorie". While eating an apple might have tangible benefits, you would still gain weight if you ate enough of them.
Still a neat concept though...