Taking a bite out of negative calorie foods

Misinformation about dieting is everywhere. You may have heard that eating grapefruit or celery burns up more calories than are in them so they are "negative calorie foods" - myth or truth?

Unfortunately the concept of negative calorie foods is more of a diet myth than a reality. Some foods may give your metabolism more of a boost than others, and some contribute so few calories to begin with that they do require a couple of extra calories for digestion. While it is true that digesting food burns calories, it is not true that any food has negative calories. And sadly, the extra calories burned won't be enough to affect your weight.

The whole "negative calorie" concept stems from what is called the Thermic Effect of Food. The thermic effect represents the energy expenditure above the resting metabolism that contributes to digestion and storage of food. In other words you have to burn calories to get calories out of digested food. Thermic effect of food generally accounts for about 5 percent to 10 percent of all calories consumed and not really calculated for individual foods. Rather it is estimated based on all of your calories for a day. A 2,000 calorie intake uses about 200 calories to digest and store the food. Foods with high fiber content, like fruits and vegetables have a higher thermic effect (around 20 percent). But they are nowhere near 100 percent, so they obviously can't have negative calories. The thermic effect is automatically included in the calculations that estimate a person's total energy needs.

Now, if this information has made you feel a little depressed, fear not. Fruits and vegetables are naturally low in calories. One stalk of celery has about 10 calories and a cup of grapefruit about 80. You would need to eat 10 stalks of celery to get 100 calories. That's a ton of celery to chew! That same amount of calories can be found in four chocolate kisses. Get the picture? Complete weight loss plans have been designed and marketed around negative calorie foods. But the real value of these foods comes from their low calorie status. So pile those vegetables onto your plate and enjoy their delicious, nutritious and low calorie benefits.