'Obese' BMI does not harm current health of young adults, study says

A study examining the relationship between body mass index (BMI) and illness suggests that a BMI of 30 or above, a signal of obesity according to federal health standards, does not translate into current illness among adults under age 40.

In addition, researchers found that across all age groups studied, from 25 to 70 years, there was little difference in the current health status in normal-weight vs. overweight people based on the medications they took.

Body mass index is a common health measure of weight relative to height. According to the National Heart, Lung and Blood Institute, a BMI between 18.5 and 24.9 indicates normal weight and a BMI between 25 and 29.9 falls into the overweight range. A BMI of 30 or higher indicates obesity.

The researchers acknowledge that health problems in older adults with BMIs of 30 or higher might be traced back to carrying extra weight in young adulthood. Among people age 40 or older, use of medication was significantly higher among adults considered to be obese compared to adults with a normal weight.

However, the large population study suggested that people with a BMI in the overweight range are generally not at a higher risk for current health problems compared to people of normal weight, regardless of age.

"A lot of people make a big deal about those overweight BMIs, but we didn't see a difference between overweight and normal-weight adults across all age groups in the percentage of people medicated, or in the number of medications taken," said Brant Jarrett, lead author of the study and a doctoral student in neuroscience at Ohio State University.

"For college-age adults, this should help them realize that they don't have to worry so much if they have a BMI of 27 or 28. Some young people with these BMIs feel like, 'I'm going to have all these problems, I need to try 50 different diets.' And what is all that stress and dieting doing to your body? Probably more damage than the extra 15 pounds is," Jarrett said.

The study also upholds previous findings that more women than men take medication, but does not indicate why that is. Interestingly, that gender difference disappears in adults age 55 and older.

Jarrett conducted the research with colleagues while he was a graduate student at Brigham Young University. The work is published in a recent issue of the International Journal of Obesity.

Jarrett noticed during his studies on stress that many people, especially college students, said being overweight was one of their main stressors.

"We wanted to see at what point being overweight is a real physical stressor instead of a psychological stressor. Most studies on BMI look at risk factors, which do not assess current health. That's health risk. So we wanted to see if a higher BMI is associated with current physical health problems," he said.