"I have to think it out," he says. "How am I going to challenge the food? It's me and the food."
During one practice session, Jarvis attempts to eat a 7-pound watermelon, in seven minutes or less.
As CBS News Correspondent Richard Schlesinger reports, in his mind and in his world, Jarvis is an athlete: a star athlete in the half-baked sport of competitive eating.
"I do this everyday," he says. "Well, I kind of do it everyday. Everybody's involved."
In every sense of the world, Jarvis is a heavyweight champion.
His extra, extra, extra, extra large jacket lists his titles, and they are all official.
It's hard to tell if it's clothing or a resume.
"It's a little of both," says Jarvis.
"We are the NBA of competitive eating," says George Shea, who runs the International Federation of Competitive Eating.
Shea is only half kidding. His organization put together 70 events this year including the hot dog eating contests that led to the grand finale last July 4, when a Japanese man ate 40 ½ hot dogs in 12 minutes.
"We also are working on a hamburger circuit," says Shea. There's also a chicken wing circuit.
The rules are simple.
"You do have to eat everything on your plate, and it cannot, at any juncture, leave your mouth," says Shea.
Whoever eats the most in the allotted time wins, sometimes money, sometimes, just respect. Jarvis has won both, largely due to his technique.
"The time you spend chewing takes you right out of the game," says Jarvis. "Chewing is bad in competitive eating."
Jarvis won his latest title with a particularly chewy combination of beef and batter: chicken fried steak. At a championship contest just this month in Austin, Texas, he ate more than 4 pounds in 12 minutes. It was one more notch in his size 54 belt.