'Healthy' obese don't stay healthy for long

Health of most adults who are considered "healthy obese" declines overtime, claims a new study.

According to a study that tracked the health of more than 2,500 men and women for 20 years, the idea of "healthy" obesity is a misleading concept.

Researchers from the Department of Epidemiology and Public Health at University College London in England measured each participant's body mass index, cholesterol, blood pressure, fasting plasma glucose and insulin resistance. Health obesity was defined as obesity with no metabolic risk factors.

More than 51 percent of the healthy obese participants became unhealthy obese over the 20-year study period, while only 11 percent lost weight and became healthy non-obese. The remaining 38 percent stayed in the healthy obese category during the term of the study, while 6 percent of participants originally in the healthy non-obese category became unhealthy obese.

Lead study author Joshua Bell said that a core assumption of healthy obesity has been that it is stable over time, but they have now found that healthy obese adults tend to become unhealthy obese in the long-term, with about half making this transition over 20 years in our study. Healthy obese adults were also much more likely to become unhealthy obese than healthy or unhealthy non-obese adults, indicating that healthy obesity is a high risk state with serious implications for disease risk.

The purpose of the study was to determine whether healthy obese adults maintain the metabolically healthy profile for the long term or naturally transition into unhealthy obesity over time. No studies have examined this issue for this long a period of time.

Healthy obesity was only valid if it was stable over time, and the results indicated that it was often just a phase, Bell said.

Among the most common health consequences of obesity are cardiovascular diseases-mainly heart disease and stroke-diabetes, musculoskeletal issues, and some forms of cancer including endometrial, breast and colon cancers.

The research is published online in the Journal of the American College of Cardiology.