Men who weigh 20 percent less than average for their age and height have significantly lower death rates than other men, Harvard researchers reported Tuesday.
The 27-year study of 19,297 middle-aged men provides convincing evidence that excess weight increases risk of death, said Harvard School of Public Health researchers in the Journal of the American Medical Association. It also means that upward movements in tables of "ideal weights" may be misguided, they said.The data, collected between 1962 and 1988, found the lowest death rates among men who weighed 20 percent less than average for age and height. Those in the heaviest fifth of the group had an 18 percent greater risk of death than men in the lightest fifth.
"Body weight represents an important determinant of mortality," said Dr. I-Min Lee and colleagues.
"After accounting for smoking and illness-related weight loss, the lean do not experience greater mortality. Indeed, lower mortality was observed among alumni weighing, on average, 20 percent below the U.S. average for men of comparable age and height."
After adjusting for variations in age, smoking and physical activity, men with a body-mass-index, BMI, of 26.0 or greater had a 18 percent higher risk of death than men whose BMI was 22.5.
The BMI represents the ratio of a person's weight to height.
The direct relationship also was consistent when the alumni were grouped according to whether they had ever smoked or currently smoked, the study found.
The study by Lee and Drs. JoAnn Manson and Charles Hennekens, all of Harvard, and Dr. Ralph Paffenbarger of Stanford University, Calif., was funded by the National Institutes of Health.
Noting that the ideal weight for a 5-foot-10-inch man was considered 137 to 179 pounds in 1959, and 141 to 188 pounds in 1990, the researchers said their results call into question whether raising charts of "ideal" weights made sense.