Some foods also consume calories when they are digested

Here's something else you should know before you start counting calories.The calorie counts on nutrition labels measure how much energy the food contains,not how much energy you can actually get out of it.Fibrous foods like celery and whole wheat take more energy to digest,so you'd actually wind up with less energy from a 100 calorie serving of celery than a 100 calorie serving of potato chips.Not to mention the fact that some foods offer nutrients like protein and vitamins,while others provide far less nutritional value.