TOKYO (AP) - For those who think Japan is all fish and tofu, consider 10-year-old Sayaka Oyama’s former diet: spaghetti and meat sauce for lunch, chocolates and cookies for a snack, rice balls for dinner and sandwiches at nighttime classes. Late at night, she would slurp down some quick noodles before going to bed.

The diet had a predictable outcome - one that doctors are seeing more in Japan as the country leaves behind traditional food habits. At 9 years old, Sayaka was 4 feet 2 inches tall and weighed 108 pounds, about 50 pounds over her ideal weight.

"I just love eating noodles. I get home tired from cram school, so I used to eat it all the time at night," said the girl, who, like many Japanese children, takes evening classes to prepare for junior high entrance exams.

Sayaka is now trying to slim down in a sports program for overweight children. She reflects a rise in obesity in Japan that is being blamed for diabetes and other health problems. Some fear the trend could one day jeopardize Japan’s status as the home of the world’s longest-living population.

Life expectancy is 86 for Japanese women and 79 for men.

"I don’t know for how long Japan can maintain the world’s highest longevity," said Yukio Yamori, director of the International Center for Research on Primary Prevention of Cardiovascular Diseases. "If eating habits change, life expectancy will shorten, and this has already been made clear."

Still, the Japanese are a long way from being as fat as Americans. Only 24 percent of Japanese age 15 and older are believed to be overweight, compared with about 65 percent of adults in the United States.

But concern is growing over eating patterns such as Sayaka’s. Instead of the fish, rice and miso soup of their grandparents’ generation, younger Japanese are increasingly wolfing down fast food such as burgers, fried chicken and instant noodles.

Bad diets and less exercise create what psychologists say is a vicious cycle: Fat children are increasingly picked on at school, get depressed and find solace in eating even more.

"Children these days shoulder a lot of concerns and stresses," said Yuriko Ota, a nutritionist who runs the program that Sayaka enrolled in last year. "I feel there are more obese kids that are gloomy and dark. It wasn’t like this before."

Men in all age groups have grown heavier in the past two decades in Japan. The highest rate of obesity is among men in their 40s: 34 percent in 2003, up from 23 percent in 1980, according to the National Health and Nutrition Survey. Although older women are also growing fatter, younger, fashion-conscious women tend to be underweight.

Among children, 8 percent were obese or at risk of obesity in 2004, compared with fewer than 6 percent in 1980. In the United States, experts believe about 30 percent of children are overweight.

Diabetes is a leading concern. Although the number of deaths from the disease has fallen in the past decade, more than 2 million people are being treated for it in Japan - an increase of about 53 percent from 15 years ago.

Alarmed by the trend, the government released a new nutrition chart last summer that encourages eating more carbohydrates - such as rice - and vegetables as main sources of energy while cutting down on meat to reduce the intake of fat. The chart specifically targets overweight males, singles and those raising children.

The government has set aside about $600,000 in the 2006-2007 budget to tackle child heft. The Health Ministry also plans to research the link between parents’ lifestyles and overweight children and support selected towns to promote healthier eating habits.

Heavy children also are flocking to programs such as Sayaka’s in central Tokyo. The Health and Sports Class’ one-year curriculum is split between sports and nutrition and health lessons for children and parents.

For Sayaka, the hard work is paying off. She’s grown more than 2 inches taller since starting a year ago but has kept her weight steady. Though she’s still over her ideal weight, she’s proud of her progress.

"I stopped eating noodles every night, and now I only eat it once a week just Saturday and only for lunch," she said. "I didn’t like veggies before, but now I try to put them in everyday meals."

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