Get Busy if you want to Beat the Middle-age Spread

"Some people gain a pound a year during midlife," says Caroline Apovian, an associate professor of medicine at Boston University School of Medicine. Many become less active as they age, which is one reason for weight gain, she says.

Plus, people start to lose muscle mass at age 40 and continue to lose over the years if they don't do something to preserve it. This affects the calories they burn when active and at rest.

It also explains in part why many people today suffer from what's called "sarcopenic obesity," meaning they are overweight or obese and have suffered a progressive loss of muscle mass, says Apovian, who spoke on the topic this weekend at the annual meeting of the Obesity Society in San Diego.

There are people who don't gain weight, including athletes and people who maintain their physical activity level, eat a healthy diet with plenty of fruits and vegetables and lean protein, she says.

"Exercise makes you feel great and can stop the spread of fat to your middle," Apovian says.

A study released earlier this year by Harvard scientists showed women gain an average of 20 pounds over 16 years as they move into middle age, but those who regularly walked briskly or biked were less likely to gain as much.

Apovian is doing research to see whether having men do more strength training and eat more protein (meat, fish, eggs, low-fat dairy, nuts) can prevent muscle loss and fat accumulation. And they are having some older men take testosterone to see the effects.

As these areas continue to be investigated, she advises people to strength-train.

You don't have to go to the gym to strength-train, says John Jakicic, director of the Physical Activity and Weight Management Research Center at the University of Pittsburgh.

It can be done at home following a DVD, using hand weights or resistance bands or filling a plastic jug with water and lifting that during television commercials, he says.

Taking a brisk walk daily and doing some weight training, putting some extra resistance on the muscles and bones, "can provide benefits that will dramatically improve your health," Jakicic says.