Obesity Cuts Nearly a Decade from Life Expectancy

Obesity can deprive adults of nearly 20 years of healthy life and up to 8 years of life expectancy, according to research published in The Lancet Diabetes & Endocrinology.

Researchers from McGill University in Montreal examined data from the US National Health and Nutrition Examination Survey from 2003 to 2010 to identify diabetes and cardiovascular disease risk factors in adults with different body weights. The investigators aimed to determine the impact that being overweight or obese has on life expectancy and healthy life-years, defined as years free of obesity-associated cardiovascular disease and diabetes.

Individuals with a body mass index (BMI) between 25 kg/m² and 30 kg/m², who were classified as overweight, appeared to lose between 0 and 3 years of life expectancy, depending on age and gender. For individuals whose BMI was 30 kg/m² to 35 kg/m², years of life expectancy lost numbered between 1 and 6 years.

In observing very obese participants whose BMI was 35 kg/m² or greater, the researchers estimated that those patients lost between 1 and 8 years of life expectancy—an effect that was greatest in young adults and declined with increasing age.

“Our computer modeling study shows that obesity is associated with an increased risk of developing cardiovascular disease—including heart disease and stroke–and diabetes that will, on average, dramatically reduce an individual's life expectancy and the healthy life-years free from living with these chronic illnesses compared with people of normal weight,” explained lead study author Steven Grover, MD, in a press release.

The investigators also concluded that being overweight or obese was associated with 2 to 4 times as many healthy life-years lost than total years of life lost. Adults aged between 20 and 29 years experienced the greatest loss in healthy life-years, which amounted up to 19 years for very obese men and women.

“The pattern is clear,” Dr. Grover continued in the statement. “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. These clinically meaningful 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.”