Negative calorie food is a bit of a misnomer. There is no food in existence that contains negative calories; every food has some caloric content, however minute it may be. However, certain foods, when eaten, require more energy from your body to digest than the calories that they contain. Negative calorie food offers great nutrition, as well as the possibility of helping you lose weight simply by eating.
A negative calorie diet is based on the idea that certain foods, mostly plants, are difficult to digest because of their cellular composition, i.e., cellulose. Everything that you do — sleeping, breathing, blinking your eyes — requires a certain amount of energy, and eating is no exception. This energy is created by burning calories.
Your body requires on average 150-250 calories to digest your food, depending on your weight, gender and activity level. If you eat something that has a caloric content of 100 calories, you will actually burn more calories than you ingest. Because negative calorie food is harder to digest, your body will require more than the average 150-250 calories to digest it.
Some of the most common negative calorie foods are apples, celery, blueberries, beets, asparagus, green cabbage, spinach, oranges, strawberries, grapefruit and garlic. This list is by no means exhaustive. There are many books and recipes available concerning such foods and negative calorie dieting.
The theory that negative calorie food helps you to lose weight simply by eating has fallen under harsh criticism, as have most diets. Some contest that people who practice this diet will overeat, according to the notion that you can eat however much you want without gaining weight. The diet is also criticized because it is often not accompanied by exercise. There is no conclusive proof that negative calorie food works the way it is believed to.
However, research has been conducted that supports the claim that eating these foods assists in weight loss. Regardless of whether this diet helps the user to effortlessly lose weight, negative calorie foods are packed full of vitamins and minerals. Many of them contain antioxidants, and some are believed to prevent disease. Even if these foods don't make up a miracle diet, it is still a very healthy way to eat.