Can certain foods burn calories? I mean, can food itself actually burn calories? Nope. Just a myth.

There's this thing called the negative calorie effect, which refers to the act of chewing and digesting certain foods to burn more calories than the food itself contains. Cucumbers, celery, and grapefruit are three foods rumored to have negative calories. But they don't. The truth is, chewing only eats up about 11 calories per hour.

Low-calorie, high-nutrient foods -- like cucumbers, celery, and grapefruit -- can surely help you lose weight, but not because they create negative calories. It's because you're consuming them and not crackers, chips, and candy.

Source

All food has calories -- they can't help doing so. But, some foods take more calories to actually eat than they provide your body be having eaten them. So, the term "negative" comes from the overall net result. Chomp for 20 minutes eating a food containing 45 calories and you'll probably burn 50 calories in the process.

There have been books and countless studies done on "negative calorie" eating, and there are some people I know personally who base a good portion of their diets on eating foods that are tasty, but that require more effort to eat than the caloric count being provided. Hence, weight loss in an easy-to-swallow package.

As one would expect, most "negative calorie" foods fall in the vegetable and fruit ranges -- so no pan-fried bacon or steaks here.

Source