NEW YORK -- When 31-year-old Carlos Lazos left the Army Reserve, it didn't take long for him to gain 70 pounds.

"Started eating more fried, more fried food, a lot of fried foods," he said.

His lifestyle as a long-distance truck driver was putting him on the road to diabetes. He's now dieting and exercising, but his experience is shared by millions.

A report that the New England Journal of Medicine released Monday found that one in 10 people worldwide were obese in 2015 -- an estimated 604 million adults and 108 million children.

Carlos Lazos' lifestyle as a long-distance truck driver was putting him on the road to diabetes. CBS News

In the U.S., 12.7 percent of children were obese, the highest rate in the world. The highest percentage of obese adults was in Egypt, at 35.3 percent.

Azeem Majeed CBS News

Professor Azeem Majeed from Imperial College London is one of the study's authors. He says diets high in calories are a major reason, but there's another culprit.

"For many of these countries there's been quite a rapid change in employment away from high physical activity jobs like farming or laboring towards more low-activity jobs like working in offices," Majeed said.

Excess weight accounted for 4 million deaths worldwide, 70 percent from cardiovascular disease. And it turns out that 39 percent of those deaths were in people who were overweight, not obese.

"I think people now know that being obese is bad for your health but I think less people know that being overweight is also bad for your health as well,"Majeed said.

Someone five feet nine inches tall weighing 169 to 202 pounds is considered overweight. Two-hundred-and-three pounds or more would make that person obese.

Dr. Bruce Lee CBS News

"The health effects include different kinds of chronic diseases like type 2 diabetes … heart disease … stroke, many different cancers are associated with increased weight or being overweight or obese," said Dr. Bruce Lee, a global obesity expert at Johns Hopkins University.

Obesity is a global problem that requires more than individual willpower. One successful strategy in some communities has been having everyone work together to change the environment: putting in walking paths, getting rid of junk food in schools, and offering better choices in restaurants, making it easier to make a healthy choice.