Fitness in the Land of the Rising Sun appears to be deteriorating. Obesity in Japanese men in their 40s increased from 23 percent in 1980 to 34 percent in 2003, and among children, from roughly 6 percent to 8 percent, according to the country's National Health and Nutrition Survey. Meanwhile, the number of people being treated for diabetes shot up 53 percent over the past 15 years, while the number of patients with high blood pressure has grown 9 percent in 10 years, the Health Ministry says. This in the country that has had the world's longest life expectancy: 86 years for women, 79 for men.

It's not that the Japanese are all suddenly trying to become Sumo wrestlers. The problem is too many are eating like one. "Unfortunately, an increasing number of Japanese are adopting unhealthy eating patterns," Moriyama says. "Japanese people are just as vulnerable -- maybe even more so -- to the dangers of fast food, sedentary lifestyles, and obesity as Westerners. In other words, it's not all in our genes."

The experts agree. People in the Far East, "want to get anything American -- including all the fast food chains," says T. Colin Campbell, Ph.D., a Cornell University professor of nutrition and health, researcher, and coauthor of 'The China Study: The Most Comprehensive Study of Nutrition Ever Conducted.' "They're going toward the Western diet: Their plant food intake tends to go down while fat and animal protein intake has gone up."

The root of all this malnutrition is, of course, "money -- they are gaining wealth," says Campbell. "[In] most every society, as soon as they become industrialized and get more capital, it filters down to the average citizenry. And one of the first things they want to do is throw a side of beef on the back of their bicycle and ride home with it."

The lesson: "This is a wake-up call for Americans and the Japanese to rediscover what helped make Japan lean and healthy in the first place," says Moriyama. "Eat modest portions, lots of fish, vegetables, and rice, and less red meat, processed foods, and saturated fats. Celebrate balance, variety, and savor the beauty of food."

--Rob Medich