Are There Foods with Negative Calories?


Q: I'm a big nosher, but I don't want to gain weight. Are there any foods I can eat that actually burn calories rather than add calories?
A: The notion that certain foods contain "negative calories" has been around for as long as I can remember. The idea is that such foods would cause more calories to be burned during digestion than the number of calories the food contained.
While some foods do contain negligible calories (celery and iceberg lettuce come to mind), you still end up with a small, net positive calorie intake after they've been digested and metabolized.
The closest thing I could find to a "negative calorie" food was sugarless gum (although gum is not really a food). Researchers at the famed Mayo Clinic decided to test this "food" by having people chew sugarless gum for 12 minutes at a rate of 100 chews per minute. The researchers measured how much energy these folks expended before, during, and after the chewathon, and calculated that the act of chewing burned an extra 11 calories per hour. If you subtract the calories in the gum (typically 5), you have a 6-calorie deficit. Certainly not enough to make a difference in weight loss — but pop a stick in your mouth instead of chips, cookies, or pretzels and you're sure to prevail!