New York: As body weight increases in men, the risk of death from suicide falls markedly, new research hints.

Given that previous studies have linked obesity with depression, obesity might be expected to raise the risk of suicide, but the few studies that have addressed this topic have largely found just the opposite, Dr. Kenneth J. Mukamal, from Beth Israel Deaconess Medical Center in Boston, and colleagues note.

They looked at data for 46,755 men who participated in the Health Professionals Follow-up Study. Height, weight, and physical activity levels were recorded starting in 1986 and repeated several times until 2002 or death.

Mental health-related quality of life was determined with a standard survey in a subset of 1,829 men in 1998. During follow-up, 131 men died from suicide, the report indicates. The suicide death rate was markedly lower among men who were overweight or obese compared with men who were of normal weight.

According to the team, the suicide risk was lowered by 11 percent for each 1.0 unit increase in body mass index or BMI, a standard measure used to calculate how fat or thin a person is.

Mukamal's team also found that mental health-related quality of life improved as BMI increased.

"Further research into the mechanisms of lower risk among overweight and obese men may provide insights into effective methods of suicide prevention," the researchers conclude.