During the past several years, the body mass index (BMI), which is a ratio of an individual’s height and weight, has become a measurement of whether a person is considered healthy. Many companies in the United States use their employees’ BMIs as a factor in determining workers’ healthcare costs. In addition, individuals with higher BMIs might soon have to pay higher health insurance premiums, if a policy proposed in April by the Equal Employment Opportunity Commission (EEOC) is adopted. However, a new study led by UCLA psychologists has found that using BMI to gauge health labels more than 54 million Americans as “unhealthy,” even though they are not. The findings were published online on February 4 in the International Journal of Obesity.
“Many people see obesity as a death sentence,” noted lead author A. Janet Tomiyama, PhD, an assistant professor of psychology at UCLA. She added, “But the data show there are tens of millions of people who are overweight and obese and are perfectly healthy.” For the study, Dr. Tomiyama and her team used data from the most recent National Health and Nutrition Examination Survey; they assessed the relationship between BMI and several health markers, including blood pressure as well as glucose, cholesterol and triglyceride levels.
The researchers found that 47.4%. or 34.4 million people, in the United States who are considered “overweight” based on their BMIs are healthy; in addition, 19.8 million individuals who are considered “obese” are also healthy. Dr. Tomiyama explained that, based on other health measurements than their BMI, the individuals in both of those groups would be unlikely to sustain higher medical expenses, and it would be unfair to charge them more for healthcare premiums.
Other findings of the study were: more than 30 percent of those with BMIs in the “normal” range (approximately 20.7 million people) are actually unhealthy based on their other health data; and more than 2 million people who are considered “very obese” based on a BMI of 35 or higher are actually healthy (that is approximately 15% of Americans who are classified as very obese). Dr. Tomiyama, who directs UCLA’s Dieting, Stress and Health laboratory, found in previous research that there was no clear connection between weight loss and health improvements related to hypertension, diabetes, and cholesterol and blood glucose levels.
Dr. Tomiyama said she was surprised at the magnitude of the numbers in the latest study. She said, “There are healthy people who could be penalized based on a faulty health measure, while the unhealthy people of normal weight will fly under the radar and won’t get charged more for their health insurance. “Employers, policy makers and insurance companies should focus on actual health markers.”
Co-author Jeffrey Hunger, a doctoral candidate at UC Santa Barbara, noted that the study shows that BMI is a deeply flawed measure of health. He added, “This should be the final nail in the coffin for BMI.” He recommends that individuals focus on eating a healthy diet and exercising regularly, rather than obsessing about their weight, and strongly opposes stigmatizing people who are overweight.
The proposed EEOC policy would allow employers to charge higher insurance rates to individuals whose BMI is 25 or higher. A BMI between 18.5 and 24.99 is considered normal; however, the study emphasizes that normal BMI should not be the primary goal for maintaining good health. Dr. Tomiyama is planning a new study of individuals with high BMIs who are very healthy. Prospective participants may contact her laboratory for more information.