A few years ago, my office was taken by storm -- by celery. Someone had read that celery uses more calories during digestion than it has--so, in essence, it had something like -25 calories. My co-workers were filling up on celery, convinced that it would make them slim.

I'm not saying that celery will ever make you fat, but the truth is, there's no such thing as true 'negative calorie' foods. However, there are foods that are more calorie -efficient than others. Many produce items besides celery have been claimed to be 'negative calories' foods--things like asparagus, broccoli, strawberries and so on. So it can't hurt to stock up on these things -- I say go for it. Just do it with the knowledge that truly negative foods don't exist.

For more so-called 'negative' foods, click here.