4 in 10 American adults are now obese, CDC reports

America’s obesity epidemic is showing no signs of slowing down.

According to new data from researchers at the Centers for Disease Control and Prevention (CDC), 39.6 percent of adults in the United States were obese in 2015-2016, up from 33.7 percent in 2007-2008. 

Severe obesity is also on the rise. The report says 7.7 percent of Americans were severely obesity in 2015-2016, up from 5.7 percent in 2007-2008.

That means four in 10 adults in the United States are obese, and one in 13 is severely obese. 

The CDC’s findings are based on data from the National Health and Nutrition Examination Survey (NHANES), which the agency has been conducting annually since the 1970s. Obesity in adults is defined as a body mass index (BMI) of 30 or more, while severe obesity is a BMI of 40 or more.

There is some good news — relatively speaking — in the report.  The rate of obesity among American’s children and teenagers (ages 2 to 19) was 18.5 percent in 2015-2016. That’s up from 16.8 percent in 2007-2008, but the CDC researchers say the increase is not statistically significant. 

The report did find a statistically significant — and troubling — rise in obesity among children aged 2 to 5, however. In 2007-2008, 10.1 percent of children in this age group were obese. That figure rose to 13.9 percent in 2015-2016.

Children and teenagers are considered obese when their BMI is  at or above the 95th percentile of BMI for their age and gender. They are considered severely obese when their BMI is at or above 120th percent of the 95th percentile.

Current efforts are not working

The CDC’s findings are, of course, more than worrisome. Obesity is a major risk factor for a number of chronic diseases, including heart disease, stroke, type 2 diabetes, osteoarthritis and certain kinds of cancer. It’s also associated with many chronic pain conditions, including low back pain and fibromyalgia, which can greatly reduce people’s quality of life. 

The findings are also disheartening, however, for they indicate that current public health efforts to help slow down the obesity epidemic are not working.

The study does not give reasons for why Americans continue to pile on the pounds, but it’s becoming clear that the epidemic is driven by a complex group of factors  — ones not addressed by simply telling people to eat less and exercise more.

A systems problem

In a 2016 essay he wrote for Forbes, Dr. Bruce Y. Lee, director of the Global Obesity Prevention Center at Johns Hopkins University, explained why blaming the individual distracts from the real causes of the obesity epidemic.

“There’s no way that the more than 2 billion people around the world who are obese or overweight all agreed to lose willpower and start making poor decisions simultaneously,” Lee pointed out. 

“Obesity,” he stressed, “is not an individual problem. It is a systems problem.” Lee then explained why:

First, start with biology. Every year we are learning more complexities about appetite, digestion, metabolism and fat cells. For example, the television show The Biggest Loser showed that massive dieting and exercise often don’t work for long-term weight loss because your metabolism slows to regain the weight. Also new evidence suggests that the microbiome, the cities of bacteria that live in your intestine, may affect your digestion ad metabolism, even to the point where scientists are experimenting with feeding patients “poop” from more slender people to change patients’ microbiomes to lose weight. … 

Next, behavior is also a complex system. If it weren’t so complex then all of us would be able to control ourselves and our habits all of the time. …Your individual behavior is immersed in and governed by the complex social systems around you. … No one becomes successful without the influence of other people. And no one struggles with their weight without the influence of others, either.

Then there’s the environment. Without access to healthy food, walking and recreation areas, public transportation and other means to live a healthy lifestyle, staying healthy is difficult. If food is highly processed and contains artificial ingredients, that’s going to make a difference. If you have to drive and sit all day, that’s going to make a difference. If you are surrounded by stress that affects your sleep, that will make a difference. And mounting evidence suggests that pollution medications and other environmental factors may play a role. 

“These are just some of the systems causing obesity,” Lee concluded. “There’s also economics, culture and a number of other complexities. Until we accept that obesity is not a simple individual problem, the proper systems methods, approaches and solutions will not emerge and the obesity epidemic will continue.” 

FMI: The CDC’s report on the latest obesity rates was published in the Journal of the American Medical Association (JAMA), where it can be read in full. You can read Lee’s essay on Forbes’ website.