The study found that the most striking difference between the two men was that the competitive eater’s stomach had an enormous capacity for stretching, and that the food that was eaten during the test stayed in the stomach, rather than being emptied into the intestines, said the study’s senior author, Dr. David Metz, a professor of medicine at the Hospital of the University of Pennsylvania.
The extent to which these traits are innate or can be improved with training is not entirely clear, but a majority of elite competitive eaters who have competed in the Nathan’s contest have improved over time. “Nobody gets worse,” Dr. Metz said.
This performance curve implies that the stomach muscles of competitive eaters may lose their ability to contract back to their original size, leaving them “with a big flaccid bag for a stomach,” he said. (That’s not the only safety concern — at least seven people have died from choking during an eating contest.)
A stretchy stomach doesn’t worry the 34-year-old Ms. Sudo, who said she trains by eating large-volume foods like soups, whole heads of broccoli and “enough kale to kill a horse.” Before this year’s competition, she split a meal of 90 hot dogs with her boyfriend, Nick Wehry, who is also a competitive eater. (He ate 39.5 hot dogs, nine fewer than she did, to place third at this year’s contest.) The couple also work out in the gym almost daily. “I’ve always done better when I go into a contest leaner and more fit,” Ms. Sudo said.
In the early days of the Nathan’s competition, the winner was usually an obese man, Dr. Smoliga said. But as records have fallen, winners have become more slender. One explanation for this, he said, is that extra fat tissue surrounding the stomach acts like a band that prevents it from stretching.
Despite using the same hot dogs and buns for 40 years, the Nathan’s contest has seen performance among elite competitors rise by about 700 percent. “No other sport comes close to that when records are measured in a 100-plus year span,” Dr. Smoliga said.