With the recent rise in popularity of high-protein, low-carbohydrate diets, tens of thousands of weight-conscious consumers are wondering whether carbohydrates are good for them. Some of these diets claim that limiting carbohydrates and eating plenty of protein-rich foods are the healthiest and most successful ways to lose weight; others call for eliminating carbohydrates altogether. According to the most recent food pyramid published by the Food and Drug Administration (FDA), however, our daily diet should consist of 6 to 11 servings of breads and grains. Should the food group that composes the bulk of our diet really be limited or eliminated?

According to nutritional experts, the answer is no. "All foods have a purpose in the diet," says Nelda Mercer, a registered dietician and spokesperson for the American Dietetic Association (ADA). "As long as you follow the basic principles of balance, moderation, and variety, carbohydrates shouldn't pose a problem." Moreover, she says, "We need carbohydrates to survive."

The human body needs carbs

Carbohydrates are the body's principal source of energy, and the nutrients found in them are essential components of the human diet. They appear naturally in two distinct forms:

Both simple and complex carbohydrates contain the same number of calories as protein (4 calories per gram), and they offer a number of nutritional benefits. Both types of carbohydrates contain vitamins and minerals, and complex carbohydrates also contain fiber, a naturally occurring substance that is essential for digestion and has been associated with a lowered risk of cancer, diabetes, and heart disease.

Bad science

Why, then, are so many people turning to diets that encourage them to reduce their carbohydrate intake? The premise of these diets is that a high carbohydrate intake leads to increased insulin levels. Increased insulin, the diets claim, promotes the conversion of excess carbohydrates to fat, which the body then stores, contributing to obesity. These diets allege that by limiting carbohydrates, people can stop the fat-conversion process.

According to the ADA, however, the theory behind these diets falls short of science. Because the human body uses carbohydrates for energy, it will always burn them first, even when an excessive amount of protein or fat is consumed. In other words, says Mercer, if you eat too much, your body will store the fat and protein in your diet -- not the carbohydrates -- as body fat.

Some low-carbohydrate diets, such as the Atkins Diet, by Robert C. Atkins, M.D., are particularly appealing to dieters because they promote quick weight loss without hunger. While these plans are giving dieters results, experts say the initial weight they are losing is nothing more than water weight and, more important, that the diets are unhealthy. Without carbohydrates, the body is essentially robbed of the fuel it needs in order to function properly. Fatigue, dehydration, calcium depletion, diarrhea, and kidney problems are among the health problems directly linked to low- or no-carbohydrate diets.

Balance is the key

In excess, any substance in your diet can be unhealthy, so you may want to monitor your consumption of carbohydrates. According to the ADA, 50 to 60 percent of your daily calorie intake should be made up of carbohydrates. This means that people on an average diet (2,000 calories a day) should eat about 1,100 calories of carbohydrates every day.

Despite the claims made by low-carbohydrate diets, there is no magic combination of foods that promotes weight loss. "It's the amount of calories, not the source, that matters," Mercer explains. Experts agree that a balanced diet is the key to a healthy life, and that carbohydrates are a necessary part of that balance.