At 5 feet, 9 inches tall and 175 pounds, I have a body mass index of 25.9, which makes me "overweight." If I lost seven pounds, I'd have a BMI of 24.9, indicating what the government considers a "normal," "healthy" weight.
Yet, that weight is not normal since two-thirds of American adults exceed it. And judging from the latest research, it is not necessarily healthy, either. According to a study recently published by The Journal of the American Medical Association, people in the government-recommended BMI range of 18.5 to 24.9 are more likely to die from a variety of diseases than people with BMIs of 25 to 30.
The JAMA study updates research by Katherine Flegal of the National Center for Health Statistics and three other government-employed scientists, who two years ago scandalized the public-health community by concluding that the annual death toll associated with excessive weight was far lower than the U.S. Centers for Disease Control and Prevention had been claiming. The CDC later reduced its estimate from 365,000 deaths blamed on "poor diet and physical inactivity" to 112,000 "obesity-related deaths."
Looking at data from the National Health and Nutrition Examination Survey, Flegal and her colleagues found that people who qualified as "obese" (with BMIs of 30 or more) did indeed have a higher mortality rate than people in the "normal" range, as did those considered "underweight." But people who were merely "overweight" had the lowest mortality rate of all.
In their new study, Flegal et al. examine specific causes of death in each weight range and find that cardiovascular disease is by far the biggest contributor to "excess deaths" among the obese. Deaths from certain cancers and the combined category of "diabetes and kidney disease" also were significantly more common than in the "normal" group.
Although being merely "overweight" was associated with a higher death rate from diabetes and kidney disease, it "was not associated with mortality from cancer or cardiovascular disease." And since overweight people were significantly less likely to die from other causes, "the net result was that overweight was associated with significantly decreased all-cause mortality." Adjusting for smoking and pre-existing illness, both of which can be associated with lower weight, did not change the findings.
Standing alone, these data do not prove that plumpness is healthy or that thinness kills. But they do cast doubt on some of the more alarmist predictions made by "obesity epidemic" doomsayers.