Some people claim that certain vegetables, such as celery, actually burn fat. This claim is based on the thermic effect, which refers to the energy the body needs to digest, process, and eliminate food. They claim that the thermic effect of certain foods exceeds the calories in the food itself. Supposedly, you can eat as much of these “negative-calorie” foods as you want and actually lose weight. Which can lead a person to think, “Hey, I can eat that piece of cheesecake without gaining weight as long as I also eat a piece of celery. It balances out, right?”
Sadly, no known food provides negative calories. The thermic effect of foods is 5-35% of the calories they provide. The thermic effect of celery is about 10%. That means, when you eat a 6-calorie stalk of celery, your body uses less than a calorie to process it (thermic effect) and stores the remaining five calories. Of course, these five calories will not make you gain any measurable weight, and celery provides valuable nutrients, so enjoy. But don’t think that eating that celery stick makes you lose weight.