The Negative Calorie diet is based on a theory that some foods require more calories to digest than are contained in the foods and that this can be used to produce weight loss.
The origins of the idea of negative calorie foods are not clear. For many years, some people have speculated that if a dieter were to eat foods that were hard for the body to break down, but did not contain very many calories, that it would take more energy for the body to process the food than were acquired through the breakdown of the food.
The Negative Calorie diet is available as a 152-page downloadable e-book from the website http://www.negativecaloriefoods.com . It is put out by The Equilibria Group and is not available as a traditional book. Dieters must purchase the right to download the book to their personal computer and then can view the book on the computer or print it out if they choose. According to the website, the diet has been available since 1997.
The Negative Calorie diet is based on the idea that some foods are negative calorie foods. The diet does not claim that the foods actually contain negative calories, but instead that the digestion of some foods burns more calories than are actually contained in the foods. Foods that are higher in stringy fibers, such as celery, generally require more chewing than other softer foods. After chewing, the food is moved down the esophagus and into the stomach, where it begins to mix with stomach acid. It is then moved into the small intestine, where it is liquefied and begins to be absorbed by the body. In the large intestine, the rest of the fluids are absorbed and the waste products are excreted.
The Negative Calorie diet believes that this entire process of digestion uses many calories, and so by eating foods that are low in calories and take longer to digest, the body will actually be using more calories than are taken in from the foods. The diet claims that these extra calories required for digestion are taken from fat stores in the body, resulting in weight loss.
The Negative Calorie diet contains more than 100 foods that are considered “negative calorie.” These are mostly fruits and vegetables that are high in fiber, such as:
There are three diet plans that a dieter can select from, depending on how fast the dieter wants to lose weight. Also provided are a variety of recipes and suggestions for how to continue to include negative-calorie foods in the diet once the desired weight loss has been achieved.
The Negative Calorie diet theories have not been proven and it is considered a fad diet. However, there are many benefits to consuming many of the foods on the negative-calorie list, as long as they are not the only foods eaten. Fruits and vegetables provide many vitamins and minerals that are important to good health and may be able to help promote weight loss if part of an otherwise balanced and healthy diet. Foods that high in fiber promote satiety, so a person may feel more full after eating fewer calories. High-fiber foods also take longer to digest, helping the dieter feel full longer.
There are many benefits to losing weight if it is done at a moderate pace through healthy eating and increased exercise, not through the use of fad diets such as the Negative Calorie diet. Obesity is associated with an increased risk of type 2 diabetes, cardiovascular disease, and many other diseases and conditions. Losing weight can reduce the risks of these and other obesity-related diseases, and may be able reduce the severity of symptoms if the diseases have already occurred.
Anyone thinking of beginning a new diet should consult a medical practitioner. Requirements of calories, fat, and nutrients can differ significantly from person to person depending on gender, age, weight, and many other factors, such as the presence of any diseases or conditions. Pregnant or breastfeeding women should be especially cautious, because deficiencies of vitamins or minerals can have a significant negative impact on a baby. Because the recommended foods are very low in calories, this diet may be a very low-calorie diet (a diet involving fewer than 800 calories a day). Very low-calorie diets are generally recommended only to people facing serious health risks related to obesity and should only be undertaken under the supervision of a medical professional.
There are some risks with any diet, and these risks are especially great when the diet severely limits the foods that can be eaten. It is often difficult to get enough of some vitamins and minerals when eating a limited variety of foods. The Negative Calorie diet limits the dieter mainly to the list of foods that are believed to be negative calorie. Although fruits and vegetables are good sources of many important vitamins and minerals, they are not enough to maintain good health.
Dairy products are excellent sources of calcium but are eliminated on the Negative Calorie diet. Lack of calcium can lead to conditions such as osteoporosis and rickets. Proteins and fats are also not included in any of the foods that are considered to be negative calorie. Although too much fat in the diet can be harmful, some is required to maintain good health. Protein is also necessary for good health.
There have been no scientific studies of the Negative Calorie diet. Although it is generally accepted that food does require energy for the body to digest, the amount of energy expended depends very heavily on the body's metabolism, and there is no way for dieters to accurately measure how much energy their body is expending to digest any given food. The diet also claims that these foods will increase the dieter's metabolism, which has not been proven.
The U.S. Department of Agriculture's MyPlate, the updated version of the Food Guide Pyramid, recommends that healthy adults eat the equivalent of 2–3 cups of vegetables each day, as well as 3 cups of low-fat or nonfat dairy products, 5–8 ounces of grains each day (with half of all grains consumed being whole grains), and at least 5–6 ounces of protein each day. Because negative calorie foods tend to be fruits and vegetables, most of these requirements are not met by the Negative Calorie diet.
Snyderman, Nancy L. Diet Myths That Keep Us Fat. New York: Crown, 2009.
Hensrud, Donald. “We've Heard That Eating Negative-Calorie Foods Might Be a Good Diet Strategy. But What Exactly Are They?” MayoClinic.com . http://www.mayoclinic.com/health/negative-calorie-foods/AN02040 (accessed April 13, 2018).
Snyderman, Nancy. “Debunking 10 Myths about Dieting: There Are No Negative-Calorie Foods.” TIME.com , May 6, 2009.
Helen M. Davidson
Revised by Laura Jean Cataldo, RN, EdD