Obesity rates in American adults 20 years and older rose from 33.7 percent in 2007 to 39.6 percent in 2016, according to a recent National Health and Nutrition Examination Survey study.

The study surveyed over 27,449 adults, and defined obesity as a body mass index (BMI) of 30 and severe obesity as a BMI of 40. Obesity can cause health complications like heart disease, stroke, high blood pressure and Type 2 diabetes. In 2016, the American Heart Association reported the country spent $190 billion a year on weight-related medical bills.

Consumers spend billions of dollars per yearon everything from gym memberships to weight loss programs, yet obesity rates continue to rise. Medical ethicist Art Caplan told Boston Public Radio Wednesday that the focus on maintaining a healthy weight has to shift from methods like dieting and weight loss supplements to changing the behavior that leads to obesity.

“We've got to start getting the NIH and foundations not to study the misery of these obesity numbers, but how do you change behaviors?” Caplan said. “If I go to the doc and I’m overweight, I am going to get a sheet handed to me that says this is the diet you should follow. I’m pretty lucky if that piece of paper makes it home and didn’t make the trash before I got there. That isn’t going to really work. The doctor who I’m dealing with doesn’t really know how to counsel me.”

Caplan suggested that doctors and nutritionists could use incentives to help people who are obese lose weight.

“How do you change behaviors? Is it paying people cash? Is it having meals delivered to you? I don’t know what is it, but we've got to figure it out because it is costing too much in lives," Caplan said. 

Medical Ethicist Art Caplan is head of the Division of Medical Ethics at NYU Langone Medical Center ad the co-host of the Everyday Ethicspodcast. To listen to his interview in its entirety, click the audio player above.