Here’s how to estimate your daily calorie need:

1.   Determine your activity level.
Sedentary: You sit on your butt most of the day due to a job or lifestyle; you exercise rarely.  This would include those that watch more than six hours of TV/week.
Active: Your daily exercise is more than light walking; or you exercise aerobically for 45-60 minutes, three times every week.
Very Active: In addition to an active daily routine, you exercise aerobically for 45-60 minutes, at least five times every week.

2.    Find the “activity factor” number that best matches your level of activity:
Sedentary woman–12
Sedentary man–14
Active woman–15
Active man–17
Very Active woman–18
Very Active man–20

3.    Multiple your “activity factor” by your healthy goal weight in pounds.  For example, a 150 lb active woman wants to lose 20 lbs. and would multiply 15 (her “activity factor”) by 130 (her goal weight).  Her daily calorie need would be 1,950 calories/day, not 2250 calories/day.

4.    Remember don’t eat less than 1,200 calories/day or you will risk muscle loss and a slower metabolism, which then makes it harder to lose weight.

References:
“WeightLossNews,” www.prevention.com, September 2000, 116-117.