When quality matters: Are all calories equal?
By Dr. Georgene Collins

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A dieter's mantra is that calories in must be less than calories out. Yet is the number of calories the only thing to consider for weight loss? The answer is yes and no.

Calories are simply measurement units of energy for the body. Fitness professionals know the main sources of calories include the macronutrients — fat, protein and carbohydrates. While calorie reduction produces weight loss, the quality of the calorie greatly impacts weight and overall health. Education on the quality and quantity of calories is essential to help clients with their ideal weight goals.

Nutrient and energy density are important terms related to healthy food choices. Nutrient density describes the nutritional value of food. Energy density, in its simplest term, describes the caloric content.

The measure of energy density is related to the water content of food. For example, fresh sources of fruits and vegetables contain more water and therefore have a lower energy density or calorie amount. In addition, lower-energy dense foods typically are higher in nutrient density. For example, a baked potato is lower in energy density than french fries because frying adds fat, which raises the calorie level. Also, the nutrient-density value is lost because of the frying process.

In general, foods closest to their natural state contain the highest nutrient quality and lower levels of energy density. The nutrient-to-energy-density proportion allows more food for fewer calories — dieter's dream.

The quality of calorie sources also plays a role in digestion, insulin production and blood sugar levels. These can significantly impact weight goals. This is especially important for carbohydrate choices.

For example, complex carbohydrates found in fresh fruit or vegetables are better choices for weight loss than simple carbohydrates. To compare, complex carbohydrates take longer to digest. Slower digestion means slower rises in blood sugar and more stable insulin production. Stable blood sugars and circulating insulin aid in appetite and carbohydrate craving control.

By comparison, simple carbohydrates found in processed and baked goods digest rapidly. Rapid digestion leads to immediate elevation of blood sugar as the body tries to produce enough insulin to meet the demand. Unstable blood sugar levels lead to increased hunger and further carbohydrate cravings.

The quality measurement of carbohydrates is the glycemic index. The glycemic index measures the effects of carbohydrates on blood sugar and insulin demands. The lower the glycemic index, the lower the effect on blood sugar and insulin needs. Lower insulin needs result in better appetite control which aids weight loss.

Overall, a calorie is a calorie when it comes to basic energy needs. However, the quality of the calorie source plays an important role in achieving weight goals. Fitness professionals are in a key position to help clients choose high-quality foods. Recommending foods in their most natural state with little to no processing, and carbohydrates with low glycemic index ratings will help clients choose proper nutrition for lifelong weight management.

Dr. Georgene Collins, Ph.D., RN, CPHQ, is a registered nurse and women's weight loss mentor. Collins, once obese, has maintained her 145-pound weight loss since 2005. Collins maintains certification in nutrition, weight management and wellness through the American Fitness Professionals and Associates. You can learn more about weight loss and weight management at www.DrGeorgeneCollins.com.