Japan's traditional diet of fish, tofu, vegetables and rice is considered a healthy role model the world over, but a change of eating habits is weighing down the land of the rising sun.
Japan's health ministry estimates that every second male and every fifth female over the age of 40 is obese and experts have identified a change in lifestyle as the main cause of the problem.
"The everyday habits among the Japanese have become rather chaotic," explained healthcare expert Masayo Kaneda of Tokyo's University for Nutrition Sciences.
The busy lifestyle starts early, with students attending private 'juku' (tuition) classes after regular school hours and returning home very late, just as their working parents do.
With no time to cook meals, the family dinner has been replaced by ready-to-eat meals, which are often nutritionally deficient, or children are given money to buy food themselves.
Students on their way home after juku classes can often be seen snacking potato chips on commuter trains or chowing down fast food.
"As more and more mothers took up jobs, many of them had no time for cooking," Kaneda lamented.
Adding up the calories are Japanese versions of western food such as Tonkatsu, a breaded, deep-fried pork cutlet 1-centimetre thick and sliced to bite sized pieces, served on rice.
The increase in the number of Japanese at risk of developing metabolic disorders associated with obesity, high cholesterol and increased risk of heart disease and type-2 diabetes has tipped the scales and the government is calling on the nation to lose weight.
As of March 2008, companies will be required by law to subject all employees over 40 years to a medical check-up which will include a hip circumference measurement.
A hip circumference above 85 centimetres for males and 90 centimetres for females is considered obese and at high risk of developing metabolic disorders.
Companies will have to provide counselling on fitness and nutrition to those high-risk employees, business newspaper Nikkei reported recently.
To comply with these new regulations, car manufacturer Toyota will launch a health centre January 2008 incorporating the latest diagnostic equipment, the newspaper said.
Despite the phenomenon of obesity among older Japanese citizens, many young females have the problem of weighing too little.
An estimated 20 percent of Japanese females in their 20s and 30s are underweight.
They pick at low-calorie lunch packs that are also becoming increasingly popular among men in the 30s and 40s, the newspaper reported.
Additionally, the government has resolved to change the eating habits of students through improved school lunches and thus, indirectly, the nutrition habits of their families.
A system that was introduced two years ago requires that each school kitchen employ at least one nutritional expert.
In addition, older citizens are recruited to take children to the countryside and plant vegetable gardens.
"If we change the habits of children, we can also change their families and, in the long term, improve our entire society in terms of nutrition," said Kaneda.