A Japanese man who set a world record by wolfing down dozens of hot dogs within minutes has suffered a severe jaw injury due to his rigorous training, making his next title uncertain.

Takeru "Tsunami'' Kobayashi said he can only open his mouth to make a gap the size of a fingertip after being diagnosed with jaw arthritis.

In an entry on his blog entitled "Occupational hazard,'' Kobayashi said: "My jaw refused to fight any more.''

The injury occurred only a week after the slender 29-year-old started training to win his seventh straight title at the annual July 4 Nathan's Famous hot dog eating event at New York's Coney Island.

"I feel ashamed that I couldn't notice the alarm bells set off by my own body,'' he said.

"But with the goal to win another title with a new record, I couldn't stop my training so close to the competition.

"I was continuing my training and bearing with the pain but finally I destroyed my jaw.''

Kobayashi, who has become a niche celebrity in Japan and the United States, had already halted his competitive eating activities for several months due to mourning after his mother's death earlier this year.

But he said he still wanted to go to the competition in New York.

"I want to be the pride of my mother,'' he said in the blog entry posted on Sunday.

Last year, Kobayashi put down a world-record 53 and three-quarters hot dogs in just 12 minutes.

In addition to the Nathan's Famous titles, he holds world records for scoffing cows' brains and rice balls.

In 2004, he founded the United Food Fighters Organization in hopes of making people take competitive eating seriously as a sport.

Despite Japanese people's reputation as moderate eaters, Kobayashi helped to turn competitive eating into a television sensation with "food fighters'' downing everything from sushi to cakes.

Japanese television, however, began to shy away from such contests after a 14-year-old junior high school student choked to death in 2002 trying to imitate competitive eating during school lunch.