Likening obesity’s risks to those of smoking, a large European study spanning decades has found that young men who were overweight at age 18 were as likely to die by 60 as light smokers, while obese teens, like heavy smokers, were at double the risk of dying early.

While obesity is linked to a slew of health problems, the new findings fly in the face of numerous recent studies showing that people who are merely overweight may not be at higher risk of premature death than those of normal weight.

The new study, published in this week’s British Medical Journal, tracked the death rates of 45,920 Swedish men over 38 years. The researchers found that men who were obese when they signed up for service in the Swedish Army in 1969 and 1970 were at more than twice the risk of dying by age 60, compared with those who were of normal weight. That is about the same increase in risk faced by normal-weight recruits who smoked half a pack of cigarettes or more a day.

Recruits who were overweight but did not smoke were about one-third more likely to die prematurely, an increase in risk about the same as that for men of normal weight who smoked up to 10 cigarettes a day, the study found.