A growing number of Japanese children have weight problems that could set them up for health problems later in life, and standards must be set to deal with the issue, researchers said on Monday.

The Japanese are among the longest-lived people in the world, a phenomenon many attribute to a healthy diet. But health officials say millions of Japanese men and women now suffer from metabolic syndrome, a combination of medical disorders that raises the risk of heart disease and other problems.

Now a team of researchers has found that up to 20 percent of primary and junior high school children who were classified as overweight, and as many as 3 percent of children of the same age in general, may have the same condition.

“There’s a worldwide trend towards more weight problems in children, and Japan is no exception, as it has taken up habits more like the West,” said Takehiko Ohzeki, professor and chairman of Pediatrics at central Japan’s Hamamatsu University, who headed the research.

“Diet has really changed. Also, children now tend to sit around and watch TV and play computer games all day.”

The research, which took two years and which Ohzeki said may have involved up to “several thousand” participants, suggested setting standards for metabolic syndrome in children as one part of a general programme to tackle the issue.

A large waistline, high blood pressure, raised insulin levels, excess body weight and abnormal cholesterol levels are all symptoms of the syndrome.

Anyone with three or more of these conditions is considered a sufferer, and may be at higher risk of heart disease and strokes as well as diabetes.

Ohzeki’s research proposes standards such as waist measurements of 80 cm (31.50 inches) and above, along with blood pressure and cholesterol figures, as a way of determining whether children are at risk from the syndrome.

Currently, the standards for adults are waists of 85 cm and above for men and 90 cm or above for women.

Using these standards, researchers found that 5 to 20 percent of primary and junior high school children classified as overweight, and 0.5 to 3 percent of children of the same age overall were at risk from the syndrome.

“What we need to do is give guidance about how to establish good, healthy lifestyle patterns. There are a lot of habits that need fixing,” Ohzeki said.

A Health Ministry official said further research and discussion was needed before national standards are set.

In an effort to encourage healthy lifestyles, two top officials at Japan’s Health Ministry last December began a blog about their efforts to lose weight that included photos of their bellies and details about their diet and exercise.

Their efforts appear to be bearing fruit. As of mid-March, one man had lost 4.2 kg and the other 4.4 kg.