A study in the March Journal of Occupational and Environmental Medicine, says obesity adds more to health care costs than smoking.

Researchers at the Mayo Clinic analyzed the additional costs of smoking and obesity among more than 30,000 Mayo Clinic employees and retirees. All had continuous health insurance coverage between 2001 and 2007.

The study, by James P. Moriarty and his co-authors give new insight into the long-term costs of obesity and smoking, which both caused higher health costs in the seven-year follow-up period of the study.

Their report shows obesity and smoking were both associated with excess costs for health care. In a comparison with nonsmokers, average health costs were $ 1,275 higher for smokers. The incremental costs associated with obesity were even higher: $ 1,850 more than for normal-weight individuals.

For those with morbid obesity, the excess costs were up to $ 5,500 per year. The additional costs associated with obesity appeared lower after adjustment for other accompanying health problems (comorbidity).

“This may lead to underestimation of the true incremental costs, since obesity is a risk factor for developing chronic conditions,” Moriarty and colleagues write. Smoking and obesity place a growing strain on an already stretched healthcare system. Many employers are now evaluating wellness programs to lower their costs by reducing health risk factors.