Vice Health, Labor and Welfare Ministers Noritoshi Ishida and Keizo Takemi were both pictured on their blog lifting up their white shirts as female dieticians measured their flab.

The duo will keep regular commentary and show their measurements over the next six months as they try to trim down.

Both have been diagnosed with metabolic syndrome, in which people have too much fatty tissue around the abdomen.

"I have given myself a challenge and decided to open up the diary of my struggle," Ishida wrote on the "Metabo Busters" blog.

The 55-year-old said he would try to walk for 10 minutes a day, would not use elevators if possible and limit his alcohol intake to one can of beer a day.

"Conquering metabolic syndrome is key to achieving the goal" of reducing diabetes in Japan, Ishida said.

"However, even though I'm in charge of this, I have metabolic syndrome as I weigh 88 kilograms (193 pounds) and have an abdominal circumference of 101.5 centimeters (41 inches)," said Ishida, who hopes to lose six kilos and six centimeters of belly.

Takemi, who is also 55, has set a goal of losing five kilograms and squeezing his abdominal circumference by five centimeters.

"I will be under pressure to make a very serious effort as I love delicious foods," Takemi said.

"But I want to send a message: 'If Takemi can do it, everybody can do it'," he said, pledging to eat only one sweet a day.

Obesity is on the increase in Japan despite the nation's traditionally healthy diet and lifestyle.

Some 9.4 million people in Japan are diagnosed with metabolic syndrome and another 10.2 million are at risk out of a population of some 127 million people, according to official figures.

The officials' blog is available at http://www.mhlw.go.jp/bunya/kenkou/metabo/index.html.