Overweight warning: More than exercise needed (Reuters)

CHICAGO (Reuters) - Exercise will not cut the risk of heartdisease in those who are overweight unless they also slim down,according to a study of thousands of U.S. women published onMonday.

"Even high quantities of physical activity are unlikely tofully reverse the risk of coronary heart disease in overweightand obese women without concurrent weight loss," Dr. AmyWeinstein and colleagues at Boston's Beth Israel DeaconessMedical Center reported.

"Regardless of body weight, (the findings) highlight theimportance of counseling all women to participate in increasingamounts of regular physical activity and maintaining a healthyweight to reduce the risk of coronary heart disease," theyconcluded.

The study, appearing in the Archives of Internal Medicine,was based on information from a study of nearly 39,000 womenthat began in 1992 and traced a number of health issues.

The researchers said 34 percent of the women in the studywere physically active based on government guidelines, 31percent were overweight and 18 percent were obese.

In the end, 948 women were diagnosed with heart disease.Active women with normal weight had the lowest risk ofdeveloping heart problems while there was a slightly higherrisk for those with normal weight who were not active.

The risk was next highest for active women who were eitheroverweight or obese, and highest for similar women who wereinactive.

Fat cells produce chemicals that can speed up hardening ofthe arteries and increase inflammation, the researchers said,harming blood vessels, while physical activity makes forhealthier blood vessels and reduces the risk of blood clots.

(Reporting by Michael Conlon; editing by Maggie Fox andBill Trott)