We have used the term healthy obesity to describe a population that appears healthy and has a BMI that classifies them as obese. But is the term healthy obesity misleading?
In fact, new research shows us that so called healthy obesity actually progresses to unhealthy obesity in most adults in a new small but long-term study
The researchers point out that the idea of "healthy" obesity is actually a misleading concept in that most obese individuals become progressively less healthy over time. This data comes from a study that tracked the health of more than 2,500 men and women for 20 years.
The research is newly published in the Journal of the American College of Cardiology.
Researchers (Department of Epidemiology and Public Health at University College London in England) studied 2,521 men and women between the ages of 39 and 62, measuring each participant's:
- body mass index
- cholesterol
- blood pressure
- fasting plasma glucose
- insulin resistance
Healthy obesity was defined as obesity with no metabolic risk factors. More than 51% of the healthy obese participants became unhealthy obese over the 20-year study period, while only 11% lost weight and became healthy non-obese. The remaining 38% stayed in the healthy obese category during the term of the study, while 6% of participants originally in the healthy non-obese category became unhealthy obese.
The authors point out that a core assumption of healthy obesity has been that it is stable over time, but we can now see 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.
Among 2,521 participants, 181 were initially classified as obese, including 66 who were classified as healthy obese. After five years, 32% of the participants initially classified as healthy obese had become unhealthy obese. By 10 years, 41% were unhealthy obese, 35% were unhealthy obese at 15 years, and more than 51% were unhealthy obese at the 20-year mark.
In contrast, only 6 percent of the healthy obese participants lost weight and became healthy non-obese at the end of the first five years of the study. The healthy non-obese portion of participants changed from 4.5% after 10 years to 6.1% after 15 years and to 10.6% after 20 years.
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.
The authors state "healthy obese adults show a greater risk for developing cardiovascular disease than healthy normal-weight adults, although this risk is not as great as for the unhealthy obese. Healthy obesity is only a state of relative health - it's just less unhealthy than the worst-case scenario. And as we now see, healthy obese adults tend to become unhealthy obese over time, providing further evidence against the idea that obesity can be healthy".
The authors summarize-"Healthy obesity is only valid if it is stable over time, and our results indicate that it is often just a phase. All types of obesity warrant treatment, even those which appear to be healthy".
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.
