When your calorie intake consistently equals your calorie expenditure, you will maintain your current weight. When you consume more calories than you burn, you will gain weight. Likewise, if you eat fewer calories than you use, you will lose weight.

The trick to maintaining, gaining or losing weight is to find out how many calories, on average, you burn per day, and to adjust your intake accordingly. For example, if your goal is to lose 10 lbs., and you burn 2,200 calories per day, then trimming 500 calories from the amount you burn (i.e., keeping your daily intake at 1,700 calories) will enable you to lose approximately 1 lb. of fat per week (1 lb. of fat equals about 3,500 calories). After 10 weeks you would reach your goal!

Don’t worry about crunching the numbers yourself. Let this interactive calculator do the planning for you. Just fill out the information requested to get an estimate of the:

• Number of calories you burn in a day
• Number of calories you should consume per day to meet your weight goal
• Recommended daily amount of key nutrients (vitamin C, folate, calcium, etc.) and food types (carbohydrates, proteins and fats) you should strive to get through your diet.

Use the following guidelines to determine your physical activity level.

• High activity: Paticipation in vigorous physical activity for 60 minutes or more at least 4 to 5 days per week or having a job that is very physically demanding (such as a roofer or aerobics instructor).

• Intermediate activity: Participation in moderate physical activity like swimming, jogging, or fast walking, 2 or 3 times a week, 30 to 60 minutes each time.
• Low activity: No planned, regular physical activity; occasional weekend or weekly activity is the only type of physical activity (like golf or recreational tennis).