How Many Calories Do We Really Need?
Mar 11, 2014
Healthy eating patterns and physical activity to help reduce the risk of chronic disease are the hallmarks of the scientifically reviewed 2010 Dietary Guidelines for Americans. Recognizing that obesity and overweight affects at least 65 percent of Americans, one of the key recommendations from these guidelines involves the need to balance calories to manage weight. This is based on the premise that we can prevent and/or reduce overweight and obesity by monitoring caloric intake and expending additional calories through physical activity.
Losing weight is undoubtedly challenging. Adding to the frustration is the fact that dieters often find that eating too many or too few calories often stalls their weight-loss progress. A healthy rate of weight loss is between 0.5 and 2 pounds per week. And because most of us want it off quickly, we often assume that dropping calorie intake even lower will help. Unfortunately, consuming too few calories causes the body to begin conserving energy necessary for other functions. This translates into a slower metabolism, which makes it even more difficult to lose weight. Too few calories also makes it challenging to ensure your diet contains all the essential nutrients you need to stay healthy. Therefore, the most successful approach involves the right combination of exercise and nutrition based on the specific needs of the individual.
The Daily Caloric Needs Estimate Calculator, which can be found in the Healthy Living section of the ACE website, is a great tool for estimating the number of calories needed to maintain your current body weight (i.e., energy balance), based on your age, weight, height and gender. Whether your goal is to lose or gain weight, you simply apply the standard energy equation that uses a formula of 3,500 calories equaling 1 pound. This means that to lose (or gain) 1 pound per week, you would need to either decrease (or increase) calories by approximately 500 each day from the original energy balance calculation—either through food, exercise or a combination of both (500 calories x 7 days/week = 3500 calories). With weight loss in particular, the most effective approach includes creating that deficit through a combination of a little less food and a little more exercise (DHHS, 2005). For example, if your goal is to lose 1 pound per week, each day you could consume 200 to 250 calories below your energy balance number, and expend 200 to 250 more calories through physical activity.
Many popular diets and weight-loss programs are based on the concept of energy balance. They often add their own trademarked spin with things like pre-calculated meals, points, lists of acceptable foods, etc. Regardless of how it’s packaged and presented to the weight loss consumer, it all comes down to one thing—creating an ideal calorie deficit.
U.S. Department of Agriculture: Dietary Guidelines for Americans (2010). Retrieved 02/23/2014, fromhttp://www.cnpp.usda.gov/publications/dietaryguidelines/2010/policydoc/policydoc.pdf
U.S. Department of Health & Human Services (DHHS), AIM for a Healthy Weight (2005). Retrieved 02/23/2014, from http://www.nhlbi.nih.gov/health/public/heart/obesity/aim_hwt.pdf