What Are Good Calories?

Everyone needs calories. They supply fuel to your muscles, brains, heart and all your other organs. In that universal context, calories are good because they keep you going. However, too much of a good thing can be bad. Excess calories lead to weight gain and increase your risk of health problems. In addition, in the context of typical American eating, with high-fat, processed, salty and sugary foods and beverages, some calories are definitely better than others. A good calorie provides the most amount of nutrients in the least amount of energy.

What is a Calorie?

A calorie is a unit of measurement for energy. Practically speaking, it is based on the amount of heat energy needed to raise the temperature of 1 gram of water by 1 degree Celsius. Although you commonly hear foods' energy expressed as calories, the actual term for it is kilocalories, or kcals for short. Of all the nutrients you consume on a daily basis, only fats, carbohydrates and proteins supply energy and therefore have calories. Fats supply 9 calories per gram, and carbohydrates and proteins provide 4 per gram. Theoretically, 3,500 calories equals 1 pound of body weight, but just because that's how it shakes out in a laboratory doesn't mean that's how it will work for you. Your weight also depends on the source of your calories.

Elements of Good Calorie

Considering the numerous health issues related to the way you eat, you might be a little suspicious of the age-old saying, "A calorie is a calorie." Public health authorities, such as the those at U.S. Department of Agriculture, agree that some calories are better than others. The Dietary Guidelines for Americans 2010, for example, stresses the need for "nutrient-dense" calories. These are healthy eating patterns in which you consume foods that supply all the nutrients you need within the fewest amount of calories. Nutrients not only include fat, carbs and proteins, but also vitamins, minerals and water. Good calories also are found in foods that are low in solid fats and added sugars. In addition, the guidelines advocate good calories can be judged by how the food was prepared. Fresh is better than processed; baked is better than fried.

Bad Calories

A growing number of researchers link the type of carbohydrates you eat with health problems, such as obesity and heart disease. For example, pediatric endocrinologist David Ludwig of Harvard's Children's Hospital Boston says rapidly digested carbs -- processed and sugary carbs -- break down so fast that they spike your insulin. Over time, these "bad" carbs, and thus bad calories, spur weight gain. In "Good Calories, Bad Calories: Fats, Carbs, and the Controversial Science of Diet and Health," author Gary Taubes echoes Ludwig. He says obesity is a hormonal problem caused by diets with excessive carbohydrates and their effect on insulin, which promotes fat storage. He said these bad calories start a vicious cycle, producing more hunger and reducing calorie burning. The American Heart Association notes that overweight and obese people tend to have high triglycerides, which is the chemical form in which most of your body fat exists. The association reports that a "diet very high in carbohydrates," 60 percent or more of total calories, can cause this elevation of triglycerides.

Calorie Balance

The focus on "good" calories plays into the larger emphasis on calorie balance. The USDA, CDC and other public health authorities state that too many Americans are in a state of calorie imbalance, which refers to eating more calories than you burn. The result is weight gain. More than two-thirds of adults are overweight or obese, and one of every three children is overweight or obese. To curb the epidemic, the Dietary Guidelines encourage you to decrease the total number of calories you eat -- good and bad -- but especially the bad. In a nutshell, eat less and move more to accomplish this.