Is overweight a misnomer?
Posted by Lance Gravlee on November 7th, 2007 |
A few weeks ago, we discussed a paper published in 2005 showing that people who are defined as overweight (BMI of 25-<30) actually have the lowest risk of mortality. Today, a new paper sheds more light on the association between BMI and mortality by looking at specific causes of death.
It turns out that people who are officially defined as overweight have a lower overall risk of mortality because they are less likely to die from diseases like Alzheimer’s, infections, and lung disease. At the same time, being overweight (but not obese) does not appear significantly to increase the risk of dying from cancer or heart disease.
In a New York Times story about this paper, several observers echoed some of our discussion in class:
Some who studied the relation between weight and health said the nation might want to reconsider what are ideal weights.
“If we use the criteria of mortality, then the term ‘overweight’ is a misnomer,” said Daniel McGee, professor of statistics at Florida State University.
“I believe the data,” said Dr. Elizabeth Barrett-Connor, a professor of family and preventive medicine at the University of California, San Diego. A body mass index of 25 to 30, the so-called overweight range, “may be optimal,” she said.
But as some of you suggested in class, mortality isn’t the only relevant outcome. Others argue that people who are overweight are more likely to develop heart disease, diabetes, and other conditions even if they are not more likely to die prematurely as a result.
On that note, another paper in today’s issue of JAMA examined self-reports of disability among people of varying weights at two points in time. They show that people defined as obese (BMI ? 30) are more likely to be disabled and that the disability gap between people in the obese and normal-weight categories has increased over time. But this finding appears to hold only for the obese category. People with BMIs in the range of 25-30—officially overweight—do not report higher levels of disability.
Causes of Death Are Linked to a Person’s Weight – New York Times
