Toronto: Being overweight or obese may decrease life expectancy by up to 8 years, a new study has warned.
The research led by investigators at Research Institute of the McGill University Health Centre (RI-MUHC) and McGill University in Montreal examined the relationship between body weight and life expectancy.
The findings show that overweight and obese individuals have the potential to decrease life expectancy by up to 8 years.
The study further demonstrates that when one considers that these individuals may also develop diabetes or cardiovascular disease earlier in life, this excess weight can rob them of nearly two decades of healthy life.
"Our team has developed a computer model to help doctors and their patients better understand how excess body weight contributes to reduced life expectancy and premature development of heart disease and diabetes," said lead author Dr Steven Grover, a Clinical Epidemiologist at RI-MUHC.
Grover and his colleagues used data from the National Health and Nutrition Examination Survey (from years 2003 to 2010) to develop a model that estimates the annual risk of diabetes and cardiovascular disease in adults with different body weights.
This data from almost 4,000 individuals was also used to analyse the contribution of excess body weight to years of life lost and healthy years of life lost.
Their findings estimated that individuals who were very obese could lose up to 8 years of life, obese individuals could lose up to 6 years, and those who were overweight could lose up to three years.
In addition, healthy life-years lost were two to four times higher for overweight and obese individuals compared to those who had a healthy weight, defined as 18.5-25 body mass index (BMI).
The age at which the excess weight accumulated was an important factor and the worst outcomes were in those who gained their weight at earlier ages, researchers said.
"The pattern is clear - the more an individual weighs and the younger their age, the greater the effect on their health.
In terms of life-expectancy, we feel being overweight is as bad as cigarette smoking," Grover added.
The study was published in The Lancet Diabetes and Endocrinology journal.