In the land of ubiquitous Coca-Cola and McDonald’s, fat people are everywhere. According to the latest statistics from the Centers for Disease Control, two-thirds of Americans now suffer from obesity—more than 160 million people. Because of the consequences of obesity, an estimated 40 million working hours are lost each year.

America has declared war on fat. Perhaps the most powerful voice in this war is that of Michelle Obama. Her campaign Let’s Move launched around the country to push for healthier food and more exercise. Obesity, she warns, is not only one of America’s greatest health risks, but also a tremendous social, cultural and financial challenge.

Experts agree that if the nation wants to reverse this trend, efforts must begin with children and adolescents. Seventeen percent of them are already obese, three times as many as 30 years ago. Because of their weight, one-third of 17- to 24-year-olds are unfit for military and police services. In Georgia, where the preference for barbecue and huge portions is high, the numbers are especially devastating. There, every fifth child is already obese.

How did we get into this predicament?

One reason is a sedentary lifestyle. When people drive to work, get out and walk into the office, get back in the car and get fast food for lunch, then drive home again and stay put until time for bed, they’re going to put on weight. But there’s more to it than just a sedentary lifestyle.

Corn and flour are cheap, and foods that are heavy in refined flour tend to be cheap. The carbohydrates in those foods aren’t easily processed, so the body tends to convert them to fat. Obesity, of course, is a major contributor to many health problems.

Some trends have started to turn in the other direction. Fewer people smoke, more people are getting at least some exercise, and fewer people drink.  Despite some improvements, poor dietary choices are still considered as one of the biggest obstacles to good health in Americans. Hopefully as behaviors improve, America can turn the corner soon.