Here's a number that might make you put down that second donut: In the United States, around 40 percent of all adults are considered obese. In Japan, the obesity rate is only one-tenth of that. We're not saying you'll never see a heavy person in Japan; you'll just need to look really hard. But compared to Americans, few Japanese ever go to a gym. They just move more in everyday life. In Tokyo, where fewer people own cars, they average at least 10,000 steps a day.