Exercise may be the best way for obese women to keep heart disease and related metabolic problems at bay, according to a new study published in the Endocrine Society's Journal of Clinical Endocrinology & Metabolism (JCEM).

Although obesity is a risk factor for diabetes and heart disease, some people who are overweight or obese are able to delay or avoid developing related key risk factors, including prediabetes, high blood pressure and unfavorable cholesterol profiles. This phenomenon is described as metabolically healthy obesity.

"Because it is such a struggle for many people to lose weight, keeping people in a state of metabolically healthy obesity offers one potential avenue for reducing the rate of cardiovascular disease," said the study's primary author, Unab I. Khan, MD, MS, of Albert Einstein College of Medicine and Montefiore Medical Center in Bronx, NY. "Our research identified physical activity as the most important factor in slowing the progression from metabolically healthy to at-risk obesity."

The researchers identified 866 women who fit the metabolically healthy obesity profile from the participants in the Study of Women Across the Nation (SWAN) Study, a multicenter, multiethnic, longitudinal study of women undergoing the menopausal transition. Over the course of the seven-year-long study, the participants' blood pressure, cholesterol and blood sugar levels were measured annually. Participants completed an annual survey regarding their physical activity.

At the end of the study, 373 women - 43 percent of the participants - had progressed to at-risk obesity. The researchers defined at-risk obesity as having at least two risk factors, including high blood pressure, an unfavorable cholesterol profile or prediabetes. Among the women who were metabolically healthy but obese, the authors found that women who had either prediabetes or diabetes were three times more likely to develop other risk factors and progress to being at risk than their counterparts.

"Although an alarming number of the participants developed metabolic risk factors during the study, the results show lifestyle changes can help lower the risk of heart disease and death," Khan said. "This demonstrates the important role exercise plays in protecting women from the adverse health effects of obesity."