Debunking the Healthy Obesity Myth

News | Adelaide Bariatric Centre

New research out of the UK lifts the veil on the idea of healthy obesity in order to determine whether healthy obese adults stay healthy in the long term.

A small but long-term study, that tracked the health of more than 2,500 men and women for 20 years, found that most healthy obesity progresses to unhealthy obesity in the majority of adults.

The study, entitled 'The Natural Course of Healthy Obesity Over 20 Years' published in the Journal of the American College of Cardiology, found that 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 Definitions

Researchers from the Department of Epidemiology and Public Health at the University College London studied more than 2,500 government employees between the ages of 39 and 62, measuring their body mass index, as well as a range of other significant health conditions, including cholesterol, blood pressure, fasting plasma glucose and insulin resistance.

'Obese' was defined as having a body mass index of 30 kg/m2 or more, while "healthy" obesity was defined as obesity with no metabolic risk factors.

The Findings

• Of the participants, 181 were initially classified as obese, including 66 who were classified as being healthy obese
• After five years, 32% of the participants initially classified as healthy obese had become unhealthy obese
• By 10 years, 41% had become classified as unhealthy obese
• After 20 years more than 51% had become unhealthy obese
• 38% of the 66 participants initially defined as being healthy obese remained in the healthy obese category for the duration of the study
• Only 6% of participants who were originally defined as being healthy non-obese became unhealthy obese
• Interestingly, the healthy non-obese category grew over time from 5% after 10 years to 6% after 15 years, and to 11% after 20 years

The study's lead author, Joshua Bell, said "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. 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.”