Now for all the low calorie enthusiasts out there, let us talk about celery which is often proposed as a negative-calorie food due to its low-calorie count, high water density, and impressive fibre content. While all that chewing and digesting of the fibrous food does burn calories, it doesn't burn a lot. It’s a food myth that celery has “negative” calories. But, with less than 10 calories per serving, it’s great to munch on to lose weight. Containing barely 16 calories per 100 grams (as per USDA), celery is ranked high among negative calorie foods and often is the source of the food myth that you get lesser calories than you can gain when chewing and munching this "negative calorie food."