Over the past few years, body mass index, a ratio of a person's height and weight, has efficiently become a proxy for whether a person is considered healthy. Lots of U.S. companies use their workers' BMIs as a factor in identifying employees' healthcare expenses. And individuals with greater BMIs might soon need to pay greater health insurance premiums, if a guideline proposed in April by the Equal Employment Opportunity Commission is adopted.
But a new study led by UCLA psychologists has actually found that using BMI to assess health improperly identifies more than 54 million Americans as "unhealthy," even though they are not. The researchers' findings are published online today in the International Journal of Obesity.
" Many people see obesity as a death sentence," stated A. Janet Tomiyama, an assistant teacher of psychology in the UCLA College and the study's lead author. "But the information show there are tens of countless individuals who are overweight and obese and are perfectly healthy."
The scientists analyzed the link between BMI-- which is computed by dividing an individual's weight in kgs by the square of the individual's height in meters-- and a number of health markers, including high blood pressure and cholesterol, triglyceride and glucose levels, utilizing data from the most recent National Health and Nutrition Examination Survey.
The study discovered that close to half of Americans who are thought about "overweight" by virtue of their BMIs (47.4 percent, or 34.4 million people) are healthy, as are 19.8 million who are thought about "obese.".
Provided their health readings besides BMI, individuals in both of those groups would be unlikely to sustain greater medical expenses, and it would be unfair to charge them more for health care premiums, Tomiyama said.
Among the other findings:.
- More than 30 percent of those with BMIs in the "regular" range-- about 20.7 million people-- are in fact unhealthy based on their other health information.
- More than 2 million individuals who are considered "extremely obese" by virtue of having a BMI of 35 or greater are in fact healthy. That's about 15 percent of Americans who are categorized as extremely obese.
Tomiyama, who directs UCLA's Dieting, Stress and Health lab, also called DiSH, found in previous research study that there was no clear connection between weight-loss and health improvements related to hypertension, diabetes, and cholesterol and blood sugar levels.
She said she was surprised at the magnitude of the numbers in the most recent research study.
" There are healthy people who could be penalized based on a malfunctioning health measure, while the unhealthy people of typical weight will fly under the radar and will not get charged more for their medical insurance," she stated. "Employers, policy makers and insurance provider must concentrate on real health markers.".
Jeffrey Hunger, a co-author of the paper and a doctoral candidate at UC Santa Barbara, said the research study shows that BMI is a deeply problematic step of health. "This must be the final nail in the coffin for BMI," he stated.
Hunger advises that people concentrate on eating a healthy diet and exercising regularly, instead of obsessing about their weight, and highly opposes stigmatizing individuals who are overweight.
The proposed EEOC guideline would permit employers to charge greater insurance rates to people whose BMI is 25 or greater. A BMI in between 18.5 and 24.99 is thought about normal, but the study highlights that regular BMI needs to not be the primary goal for maintaining good health.
Tomiyama is planning a new research study of people with high BMIs who are really healthy. Prospective individuals might contact her laboratory to learn more.
Co-authors of the International Journal of Obesity research study are Jolene Nguyen-Cuu, manager of Tomiyama's lab, and Christine Wells, a UCLA statistical expert.