Along with barbecues, parades and fireworks, Nathan's Hot Dog Eating Contest on Coney Island has long been a Fourth of July tradition.
This year, 16-time champion Joey Chestnut will not be competing due to his signing with a vegan hot dog brand. Instead, Chestnut and longtime rival Takeru Kobayashi will go head-to-head in a hot-dog eating contest streamed live on Netflix on Labor Day.
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Chestnut – who holds the world record for ingesting 76 hot dogs in 10 minutes – seems to have perfected his technique. He funnels weiners into his mouth with one hand and chews them down. At the same time, he uses his other hand to dunk the buns into cups of water, scrunching the bread into balls and shoving them into his yap behind the beef.
But how can the human body handle such abuse?
Competitive eaters expand their stomachs by gradually increasing the amount of food they ingest over a period of time leading up to competition, said Dr. Samuel Giordano, a gastroenterologist at Cooper University Health Care.
"They would sort of practice or work up to it," Giordano said. "They kind of stretch their stomach out, per se, to handle that excess amount of food."
When the competition is over, in the "offseason," the stomach slowly contracts, he said.
"The stomach is a very resilient muscle, in that it goes back, in a sense, to what it was like" before the person began to stretch it out," Giordano said.
Dr. David Metz, a retired gastroenterologist from the Hospital of the University of Pennsylvania, conducted a 2007 study about competitive eaters, because he and his team wanted to learn whether all those hot dogs "get stuck in their stomach" or whether "they pass through their stomach into their small bowels."
Through the use of barium X-rays, Metz and the other researchers monitored the guts of a speed eater and a regular, healthy person as they ingested as many hot dogs as they could in 12 minutes. The latter ate seven hot dogs before he felt like he was going to vomit. But the speed eater downed 36 hot dogs in 10 minutes.
"He just kept on eating and eating and eating and eating, and we started getting worried about his health," Metz said.
"Despite the speed eater's insistence that he felt no sensation of satiety, fullness, bloating or abdominal discomfort, we became concerned that further dilation of his already enormous stomach could be associated with a small theoretic risk of gastric perforation," Metz and his co-authors wrote. "Therefore, a decision was made to terminate the speed-eating test over the objections of our participant. When the speed eater lifted his shirt afterward, his previously flat abdomen protruded enough to create the distinct impression of a developing intrauterine pregnancy."
The researchers concluded that speed-eaters' stomachs expand to hold a rapid influx of food. Metz said he thinks this flexibility of the stomach may be partly a natural gift.
"Maybe these guys can train a little bit, but nevertheless, I think they have some innate ability up front to relax their stomachs more than other people," Metz said. "And I think it's just something that they were born with."
Both gastroenterologists said it was dangerous for people to participate in speed-eating contests, first and foremost due to the risk of choking.
Other potential health hazards that may result from speed-eating include:
• Gastrointestinal perforation, a hole in the gastrointestinal tract that can lead to internal bleeding, permanent damage of the GI tract or sepsis
• Esophageal variceal rupture, internal bleeding from ruptured veins in the esophagus that can be life-threatening
• Mallory-Weiss tear, a split or tear in the inner lining of the esophagus that does not go all the way to the esophagus wall
• Boerhaave's Syndrome, spontaneous rupture of the esophagus caused by tremendous pressure in the esophagus, such as forceful vomiting, that can cause toxic contents to leak out and a potentially result in death