The number of calories it takes to maintain your body weight depends on a variety of different factors, including age, gender, body composition and activity level. You can use a general formula to get an estimate, and then modify your calorie consumption based on whether your weight changes or stays the same. These estimates won't necessarily be accurate for everyone due to variations in metabolism. Consult a registered dietitian for an individualized plan to support your goals.
A Calorie Estimate for a 170-Pound Person
Generally, a man needs between 14 and 18 calories to maintain each pound of body weight, and a woman needs between 12 and 16 calories per pound, depending on how active he or she is. So, a 170-pound man typically needs between 2,380 and 3,060 calories per day to maintain his weight, and a woman of this size would need between 2,040 and 2,720 calories per day. For a more accurate estimate that takes other variables into account, you can use an online calculator. Plug in your weight, height, age, gender and activity level, and it calculates the number of calories you need to maintain your current weight.
Activity Level Considerations
A 170-pound person who is very active will require more calories than a person of the same weight who gets little or no exercise. Both the amount and the intensity level of an exercise affect how many calories you need to maintain your weight. For example, a 170-pound person who runs for 30 minutes at a pace of 10 miles per hour burns an extra 650 calories. The same person walking at 3 miles per hour for 60 minutes burns 280 calories, but it would only burn about 140 calories per hour of sitting and working at a desk.
Effect of Body Composition
The more muscle you have, the more calories you'll need to maintain a weight of 170 pounds, because muscle takes more calories to maintain than fat. Fat tissue burns about 2 calories per pound per day, while muscle burns about 6 calories per pound per day. Increasing your muscle mass through strength training is one way to speed up your metabolism, so you can eat more calories without gaining weight. Aim for two or three strength training sessions per week, and be sure to include exercises that target the major muscles of the body, such as those in the arms, shoulders, abdominals, back, chest and legs.
Generally, the older you are, the fewer calories you burn per pound of body weight. Your metabolism slows down about 2 or 3 percent every 10 years after you turn 20, usually because of a loss of muscle mass. Thus, a 50-year-old typically needs fewer calories to maintain a weight of 170 pounds than a 20-year-old does. If you regularly include strength training in your exercise routine, you'll be able to minimize muscle losses and the accompanying drops in metabolism. A 5-foot, 7-inch tall man who is 20 years old and weighs 170 pounds needs about 2,600 calories per day if he's sedentary or about 3,650 calories per day if he is extremely active. A 50-year-old man of the same size would only need about 2,330 to 3,360 calories per day, however.