Being obese results in a large decrease in life expectancy similar to that which results from smoking, according to a new study reported in the Annals of Internal Medicine..

Dutch researchers, examining the medical records of 3,457 U.S. adults between the ages of 30 and 59, reported that 40-year-old female nonsmokers lost 7.1 years of life and 40-year-old male nonsmokers lost 5.8 years of life because of obesity.

Obesity is defined as having a body-mass index of 30 or above. A person with a body mass index of more than 25 is regarded as overweight.

For those who were overweight but not obese, 40-year-old female nonsmokers lost 3.3 years of life and 40-year-old male nonsmokers lost 3.1 years of life expectancy.

The decrease in life expectancy was even greater for obese smokers, with obese male smokers losing 13.7 years of life and obese female smokers 13.3 years.

"Obesity and overweight in adulthood are associated with large decreases in life expectancy and increases in early mortality," the researchers concluded. "Obesity in adulthood is a powerful predictor of death at older ages. Because of the increasing prevalence of obesity, more efficient prevention and treatment should become high priorities in public health."

Other sources: Annals of Internal Medicine