Definition Of Negative Calorie Foods

In this body-obsessed culture, losing weight has become an industry with profits exceeding the gross national product of many small countries. And yet, according to the Centers for Disease Control, obesity is on the rise. There are so many fad diets and wild weight-loss secrets floating around in popular culture that it can be hard to know what's true and what's just hype. One of the more popular myths is that of negative calorie foods. The idea that certain magic diet foods take more calories to digest than they contain is not a new one. Unfortunately, as with most myths, the truth is not quite as exciting.

Theories/Speculation

The basic theory behind negative calorie foods is the belief that certain foods -- like celery and lettuce -- contain so few calories that your body actually burns more calories in digesting and processing them. This would mean that every time you ate a stalk of celery, you would burn extra calories, leading to seemingly effortless weight loss. According to Professor Alexander Chernov, in his study called "The Dieter's Paradox," done at the Kellogg School of Management, dieters are more likely to believe that adding a healthy component -- like a side salad -- to a meal actually lowers the overall calorie count for that meal.

Misconceptions

This biggest misconception in the idea of negative calorie foods is in the math. An example given by the Georgia Department of Community Health is that eating a small piece of broccoli that contains 25 calories will require your body to burn 80 calories to digest and process it. According to that math, every time you ate a small piece of broccoli, you would burn an extra 55 calories. Because it only takes a reduction of 500 calories per day to lose a pound every week, eating 10 pieces of broccoli a day would put you ahead of the game. If it actually worked that way, no one would be overweight, never mind obese.

Expert Insight

According to CalorieCounter.com, a cup of celery contains about 19 calories. But, your body only requires 2 calories to digest it. Mayo Clinic preventive medicine specialist Dr. Donald Hensrud confirms that the amount of calories needed to burn off any food is overestimated by proponents of negative calorie foods. The doctor explains that in any given day, only 10 percent of your total expenditure of energy is dedicated to digesting and processing your food. There is no way to calculate exactly how many calories are being used at any given moment, on any given meal.

Benefits

Most vegetables and fruits are very low in calories, so incorporating them into your diet is a good idea, whether they are actually negative calorie foods or not. Many fruits and vegetables have lots of fiber, which tends to fill you up, so eating a small salad before a meal can help you eat smaller portions of higher calorie foods. Fruits are high in natural sugars, which can help tame those cravings for cookies, cakes and candy. Fresh fruits and vegetables are also free of artificial ingredients and chemical additives.

Warning

Because only vegetables and fruits are believed to be negative calorie foods, eating a diet that only contains negative calorie foods will not provide the protein, calcium and other vitamins and minerals that your body needs to stay healthy and strong. According to an article in "Chowline," the Ohio State University Extension newsletter, eating a diet that consists only of so-called negative calorie foods could lead to malnutrition.