Big-Belly Blues

Katmandu, Nepal: My belly is getting bigger and bigger, which is giving me a backache. I am 28, my height is 5 feet 8 inches and I weigh 176 pounds. How can I reduce my belly without consuming much time? I am a banker and have no time to go for regular exercise.
Dr. Harvey Simon: Your height and weight give you a body-mass index (BMI) of almost 27—overweight, but not yet obese. Still, if your excess weight is mostly in your belly, you're asking for trouble. Excess abdominal fat is a strong risk factor for heart attacks, strokes and diabetes. Based on new research, I now pay more heed to my patients' waist measurements than their BMIs. Risk begins to mount at a waist size above 31 inches for women and 37 inches for men; measurements above 35 inches for women and 40 inches for men are in the danger range. Don't waste your precious time on "spot reducing" gizmos. Even liposuction is a bust; it doesn't remove fat from the abdominal organs, where it's most dangerous.

To reduce, eat less. Avoid calorie-dense foods that are high in fat and/or sugar. Substitute fruits, vegetables and whole grains, which are filling but not fattening.

You also need to exercise more. Build physically active tasks into your daily life. Climb the stairs to your office, walk to the store, do your own chores around the yard and house. Get an exercise bike, so you can burn up calories at home. Give up some sleep to get out for a walk or jog at least a few days a week. You'll be sharper at work, so you'll make back the time you put in.

If you invest some time in exercise now, you'll gain the dividend of good health in the future. You can bank on it.

Minneapolis, Minn.: Should you eat before or after exercise? I get home at about 6 and use an exercise bike or do weight training until 7:30 or 8. Then I have dinner and am in bed by 10. Should I eat first?
Exercise takes energy. That means your heart has to pump more oxygen-rich blood to your working muscles. But when you eat, your intestinal tract also demands more blood to help it digest food and carry nutrients to the rest of your body. To avoid competition between your muscles and your guts, exercise before you eat. It's particularly important advice for people with heart disease and for healthy people who exercise strenuously. For others, a light snack before exercise may be OK, but real eating should be postponed until after real exercise. Although food and exercise don't mix so well, fluids are very desirable indeed, especially in warm, humid weather.

New York, N.Y.: I am 26 years old and run six miles four or five days a week on a treadmill. Can excessive running can cause knee problems later in life? What precautionary measures should I take?
There is a longstanding debate about this, but two 2007 studies help resolve the question. In the first of these, American scientists followed 1,279 healthy adults with an average age of 53. Over the next decade, all the volunteers provided information about exercise, body weight and knee pain, and each had a series of knee X-rays. Researchers found no link between exercise and arthritis.