This has nothing to do with the rumors his jaw muscles were steroid-enhanced:

Among the records Mr. Kobayashi holds: Cow Brains: 57 (17.7 pounds) in 15 minutes, which suggests he was infected with bovinus zombius at some point in his life. Here's the best part of the story: this may be the first time real life and an Onion headline were absolutely indistinguishable.