A large number of US companies are using body mass index (BMI) to determine whether or not an employee should pay more for health insurance coverage and a new study is saying about half of those people are healthy, despite the classification, according to a story from  UCLA.

BMI is a measure of a person’s height and weight, and a rule proposed by the Equal Employment Opportunity Commission (EEOC) back in April would cause those who fall into categories of overweight or obese to pay extra for health insurance, if implemented.

Saying that many people who are overweight or obese are perfectly healthy otherwise, researchers at UCLA undertook a study to examine the link between BMI and a person’s health indicators, including blood pressure, glucose, and cholesterol and triglyceride levels.  The data was taken from the most recent National Health and Nutrition Examination Survey.

The findings revealed that about 34.4 million people, almost half of all Americans that fall into the overweight category based on BMI, are actually healthy, as were another 19.8 million categorized as obese by the calculation.

Additionally, the researchers found that 20.7 million people in the normal range for BMI are actually unhealthy based on their other health measurements, accounting for about 30 percent of those considered normal.  The data also indicates 2 million Americans with a BMI over 35 and are considered very obese, are actually healthy, when other health data is considered.

BMI is calculated by dividing a person’s weight in kilograms by the square of the person’s height in meters.  Jeffrey Hunger, a co-author on the study said the research indicates the BMI is a faulty measurement of a person’s health, and the study emphasizes BMI should not be the primary goal for maintaining good health.

A. Janet Tomiyama, an assistant professor of psychology in the UCLA College and the study’s lead author said many people see obesity as a death sentence, but the data from this study shows there are tens of millions of people in that group that are perfectly healthy.  Tomiyama added people in the overweight and obese groups will likely face higher premiums despite being healthy and that would be unfair to the individuals.

The rule by the EEOC would allow employers to charge higher rates for health insurance for people with a BMI over 25.  A  score between 18 and 24.9 is considered normal.