Calorie needs can fluctuate like your weight

Lifestyle, age and diet goals all play a role in determining the right number

By Karen Collins, R.D.
Special to MSNBC.com
Updated: 7:54 a.m. ET Aug 17, 2007

Many of today’s nutrition recommendations are based on calorie needs, whether for weight control or for foods that fit in a healthy diet.
Unfortunately, most of us apparently can't identify our calorie needs. In a 2006 survey of 1,000 U.S. adults, 88 percent of respondents could not accurately estimate how many calories they should eat every day.
Calorie needs depend on weight, age, gender and activity level, as well as individual metabolic rate. The figures from the USDA Center for Nutrition Policy and Promotion provide a rough estimate. Women ages 31 to 50 who exercise less than 30 minutes a day need about 1,800 calories daily, while men need about 2,200. Those under 30 can add 200 to that figure; those over 50, subtract 200.
Women ages 31 to 50 who exercise 30 minutes a day can eat about 2,000 calories daily, while men can eat about 2,400. Men under 30 can add 200 (sorry, women, no change); everybody over 50, subtract 200.
Finally, women ages 31 to 50 who are very active — 60 minutes or more daily exercise — need about 2,200 calories a day, while men need about 3,000. Women under 30 can add 200 (men, sorry, no change for you); men over 50, subtract 200.
For a more accurate estimate of recommended calories that reflects your height and weight, go to http://www.mypyramid.gov/ and click on MyPyramid Plan. Recalculate your needs with every five to 10 pound change, since calorie needs change with weight.
Strategies for a balanced diet
Recommended limits of fat consumption are based on calorie needs. If you multiply estimated calorie needs by 0.011, you will see your recommended maximum grams of saturated fat daily. (For example, if you need 2,000 calories a day, that equates to a maximum of 22 grams of saturated fat a day.) Those with high cholesterol may need to reduce saturated fat below this figure. A registered dietitian can help.
How much junk food is reasonable in a healthy diet? The 2005 Dietary Guidelines for Americans include a “discretionary calories allowance.” Discretionary calories represent the extra foods and drinks that supply calories without much nutritional value. The allowance is 132 discretionary calories a day for someone maintaining weight and eating about 1,600 calories a day, and 290 discretionary calories daily for someone who needs 2,200 calories a day.
Strategies for a balanced diet change with calorie level, too. On about 1,600 calories a day, five servings of grains (equal to five slices of bread) is enough, whereas someone needing 2,200 calories a day should eat seven servings daily. Someone who needs only 1,600 calories a day can meet fruit and vegetable recommendations with seven servings daily, but someone who needs 2,200 calories or more should aim for at least 10 per day.