Thursday November 02 03:06 AM EST
Yo-yo Dieting Ups Heart Disease Risk
By Anne Burke
HealthScout Reporter

WEDNESDAY, Nov. 1 (HealthScout) -- If you're thinking about shedding the 10 extra pounds you lost but somehow managed to find again, you just might want to start loving yourself the way you are.

Women who repeatedly lose weight and gain it back have less of the good kind of cholesterol that helps reduce the risk of heart disease, claims a new study.

Levels of high-density lipoprotein (HDL) -- the good cholesterol -- are particularly low in obese women who repeatedly gain and lose weight, the study says. Even thinner yo-yo dieters, whose weight goes up and down like the toy, also have lower HDL levels than women who stay at the same weight, the study says.

"We have more reasons now to believe that dieting, per se, may be harmful," says Dr. C. Noel Bairey-Merz, medical director of the Preventive and Rehabilitative Cardiac Center at the Cedars-Sinai Research Institute in Los Angeles.

If you're fat or overweight, don't diet because it doesn't work anyway, Bairey-Merz says. Instead, she says get lots of exercise and make healthy food choices, and the weight will come off.

Yo-yo dieters analyzed by Bairey-Merz and her colleagues at three other institutions had 7 percent lower HDL levels than those who didn't diet in cycles -- 52 milligrams per deciliter vs. 56 milligrams per deciliter.

Although small, she says the difference is important. Previous studies have shown that each 1 milligram-per-deciliter increase in HDL cholesterol can decrease coronary heart disease risk by 3 percent.

The findings are significant because of the scarceness of research on the possible detrimental effects of weight cycling, says Joanne Ikeda, co-director of the Center for Weight and Health at the University of California, Berkeley. .

Medical professionals should not encourage weight cyclers to continue dieting, Ikeda says.

"We should help these people adopt a healthier lifestyle and help them be fit fat people. That in itself will help them reduce their chronic disease risk," she says.

Yo-yo dieters who participated in the study intentionally had taken off at least 10 pounds at least three times in their lives.

In the United States, many of the 40 percent of adult women who diet simply end up packing the weight back on, says Marion Olson, a research associate at the University of Pittsburgh Graduate School of Public Health, who participated in the study.

And that has consequences, says Dr. Howard Hodis, an associate professor of medicine and preventive medicine at the University of Southern California.

"It's clear that this up-and-down weight losing and gaining is not a healthy thing. If what the study found is true, this just confirms that," Hodis says.

The researchers looked at 485 women who had complained of chest pains and were undergoing coronary angiography, or an X-ray examination of the blood vessels or chambers of the heart. Twenty-seven percent said they'd yo-yo dieted, with 19 percent having lost and gained 10 to 19 pounds; 6 percent had cycled 20 to 49 pounds, and 2 percent had cycled 50 pounds or more.

"We had a few people who cycled 10, 20 or 30 times," Bairey-Merz says.

The effect of yo-yo dieting on HDL levels had nothing to do with other factors, such as having a greater body mass index (your height/weight ratio), abdominal fat, smoking, drinking, lack of exercise, diabetes or race, Olson says.

Results of the study, sponsored by the National Heart, Lung and Blood Institute, appear in the November Journal of the American College of Cardiology.

What To Do

Eat lots of fruits and vegetables each day, says Bairey-Merz. "An interesting offshoot when you eat those fruits and vegetables is that you happen to lose weight," she says.

To learn more about healthy eating habits, check the Food Guide Pyramid online.

Or, you may want to read previous HealthScout articles on dieting.

http://dailynews.yahoo.com/h/hsn/20...ase_risk_1.html