Obesity shorten life expectancy by up to 8 years

Obesity has the potential to reduce life expectancy by up to eight years and cut healthy life by 19 years, as a result of diabetes and cardiovascular disease, new research published in the British medical journal The Lancet suggests.

The study used data from the US National Health and Nutrition Examination Survey to create a disease-stimulation model, which was then used to estimated the risk of developing diabetes and cardiovascular disease in adults of different body weight.

The researchers analysed the contribution of overweight and obesity to years of life lost and healthy years of life lost in US adults of various ages between 20 and 79 years old, compared to people of normal weight.

Overweight individuals (Body Mass Index 25 to <30 kg/m2) were estimated to lose between zero and three years of life expectancy, depending on their age and gender. For obese individuals (30 to <35 kg/m2) the years lost were between one and six years, whereas the very obese (35 kg/m2 or more) were estimated to lose between one and eight years.

The study also shows that being overweight or obese is associated with two to four times as many healthy life-years lost than total years of life lost. The highest losses in healthy life-years were in young adults aged between 20 and 29 years old, amounting to around 19 years for very obese men and women.

"The pattern is clear," explains Dr Steven Grover, lead author and Professor at McGill University, Canada.

"The more an individual weighs and the younger their age, the greater the effect on their health, as they have many years ahead of them during which the increased health risks associated with obesity can negatively impact their lives," said the expert.

He added that, these calculations should prove useful for obese individuals and health professionals to better appreciate the scale of the problem, and the substantial benefits of a healthier lifestyle including changes to diet and regular physical activity.