BY NEVA COCHRAN, MS, RD, LD

Losing or gaining one pound of fat is largely a matter of math. One pound of fat equals 3,500 calories, so if you’re consuming 3,500 calories more than the recommended daily amount (and you aren’t burning any significant amount through activity), you’ll gain one pound. You’ll consume 3,500 calories if you drink a 12-ounce soda every day for 23 days, eat a cup of ice cream daily for 12 days or consume 1/2 cup of peanuts every day for eight days. To lose a pound, you must consume 3,500 fewer calories or expend an extra 3,500 calories in additional physical activity or exercise. Burning 3,500 calories requires weight training for nine hours, playing tennis or cycling for seven hours or even running or swimming for five hours.

According to studies published in Eating Behaviors and the Journal of Nutrition, participants who cut their usual daily intake by 500 calories lost one pound a week over the 12- to 14-week period (500 calories per day times seven days equals 3,500 calories). A study published in the journal Obesity found that men who added 3,520 steps to their day lost about nine pounds in a year.

For more valuable fat loss tips, pick up the May/June issue of Maximum Fitness--on newsstands April 6, 2010.