This Independence Day, competitors at Nathan’s Famous hot dog eating contest may gulp down as many as 76 wieners in about the time it takes to read this article. Like ultramarathoners hoofing 50 miles or football players shaking off big hits, “speed-eating” entails natural resilience, dedicated training, and serious risks to health.

Some may see the annual Coney Island, N.Y., contest as an act of defiance, capturing the holiday spirit. When the British taxed our sugar, we fought for independence. When modern-day doctors tell us to eat fewer carbs that turn quickly into blood sugar, we devour as much as possible on ESPN—and walk away seemingly unscathed. 

But this gastric rebellion could damage the body, during competition and over the long haul. 

A dangerous trek through the body

Mouth

Competitors typically fast before the event, says Miki Sudo, the winningest female champion in the history of the sport with nine Nathan’s titles in the women’s division. “You want the stomach to be empty and hungry” on gameday, she says.

After a rousing national anthem, a horn signals participants to eat as many hot dogs as possible in a breezy 10 minutes. Thus begins a blur of chewing and swallowing with a physicality that’s half-shark, half-snake. According to the ESPN documentary series 30 for 30, competitors train to strengthen their jaws so they can rip apart food with fang-like efficiency and desensitize their gag reflexes to gulp large pieces that would make the rest of humanity retch.

Esophagus

Just five seconds into this self-proclaimed “Super Bowl of competitive eating,” bits of hot dog arrive in the esophagus, the tube that goes to the stomach. Because they’re not chewed enough, though, chunks can slide into the airway, which can cause choking. Paramedics stand ready to assist, but across all speed-eating contests, choking is the biggest risk, and can result in death.

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As hot dogs accumulate in the body, so do more risks. The stomach can’t accept the food as fast as it’s coming, so it piles up in the lower esophagus. This traffic jam could cause the food to come back up forcefully, which can lead to choking, rips in the esophagus, and surgery to fix them, says Dr. David Metz, a retired professor of gastroenterology at the University of Pennsylvania who has studied the effects of speed-eating.

Stomach

In just two minutes, some participants may have already packed ten hot dogs into their stomachs. To accommodate this barrage, the stomach begins to expand. Normally, our stomachs enlarge like a balloon, with greater pressure as the meal goes on—and this pressure triggers a newsflash to the brain that we’re full. But speed-eaters have trained with increasingly large food quantities to increase the elasticity of their stomach, so it stretches more like spider silk. Without the same pressure build-up, their brains receive no “drop your hot dog” message—only the crowd’s roar to keep gorging.    

Small intestine

Seven minutes into the contest, some pioneering pieces of hot dog have already raced through the stomach to explore the small intestine, an organ dedicated to further digesting food and absorbing nutrients. However, this important job may be sabotaged when dealing with as many as 22,800 calories in a single meal.

One issue is that way too much glucose—the broken down form of all those hot dogs, especially their buns—could get dumped into the small intestine, Metz explains. The influx would send the body into panic mode as it seeks to avoid organ damage. This stress response, known as “dumping syndrome,” involves heavy sweating, rapid heartbeat, nausea, and diarrhea.

More research on dumping syndrome is needed, Metz says. For his study, Metz took X-ray images of one speed-eater in action and found that rapid feasting was enabled by “remarkable” stomach expansion, not by food dropping quickly into the small intestine to make room for more. This suggests dumping syndrome may not be a risk, though some competitive eaters report symptoms of the syndrome, such as profuse sweating.

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Another problem: many hot dog pieces stay mostly undigested even after making it through the stomach’s churn, says Kathleen Melanson, a professor of nutrition and director of the Energy Balance Laboratory at the University of Rhode Island. These chunks may be fermented by bacteria in the small intestine, which could cause bacterial overgrowth, Melanson says, leading to abdominal pain and diarrhea, among other symptoms.

Examples of debilitating symptoms, such as severe pain requiring a five-day hospitalization, have been documented, albeit rarely. “That doesn’t mean more haven’t happened,” Metz says. Not helping matters: the feast can stay in the digestive tract for multiple days before it’s finally expelled.

Destined to devour 

Thinking you can eat scores of hot dogs because you saw it on TV is like trying to climb El Capitan without ropes because you saw Free Solo. “No one at home should try this,” Metz says.

Professional gluttons gradually increase their intake of food over long periods of time. (They do not practice by chugging water, which can lead to brain swelling.) “There’s clearly a training effect,” says James Smoliga, a sports medicine researcher at Tufts University. He found that elite competitive eaters reliably enhance their performance with years of practice, such that their rate of scarfing resembles grizzly bears.

The improvement likely builds on physiologies uniquely suited to speed-eating, Smoliga says. Sudo thinks she’s always had “natural stomach elasticity,” and Melanson notes that twin studies suggest some people are biologically faster eaters than others. This inborn “talent” could confer some protection from the harms. 

Unknown long-term harms

Far from being overweight, many speed-eaters appear healthy. “They’re physical specimens,” Metz says. “There are no physical side effects for me yet from doing this,” other than some discomfort and sweating right afterward, says Nick Wehry, who is a competitive eater ranked fourth worldwide (and Sudo’s husband). “Many of us have a love for fitness,” Sudo says—a passion reinforced by the desire to reduce the risks of competitive eating, she adds.

Whether this strategy will result in healthy aging is yet to be seen, since the “sport” (and the study of it) is relatively new. (Major League Eating, the body that oversees pro contests, including Nathan’s, did not respond to a request for comment about whether they track the long-term effects of competitive eating.)

One long-term concern is that their stomachs have permanently expanded, so they’ll never feel full again, no matter how much they consume. “We don’t know if or how you can train it back after you’re done competing,” Melanson says. To avoid obesity, former competitors could simply remind themselves to stop eating, without relying on their stomach’s signals. But this is “challenging and takes practice,” explains Melanson, who studies people trying to slow their rate of eating, which may help with weight loss and overall health. 

Eating champ Takeru Kobayashi may have disabled his stomach’s signals after decades of competition, according to the recent documentary Hack Your Health. “I overeat because I’m a competitive eater,” he says in the film. “When you eat too much, you don’t savor the taste or fully enjoy the smell of the food. You ignore your body’s signals, like fullness.”

However, Sudo and Wehry say that after many years of competing, they still have normal appetites. 

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A permanently stretched stomach could also result in gastroparesis, where the stomach takes too long to empty, resulting in chronic nausea, pain, and vomiting.

Tim Janus, a 47-year old ex-competitive eater who Metz has studied in scientific research, quit the sport in 2016 after 11 years “out of an abundance of caution” partly based on Metz’s findings about the risks. He was also concerned about the harms of throwing up following competition, a practice that he describes as widespread. “When you’re eating that much food, you can’t digest it all,” he says. “Your stomach is too full to move things along. Throwing up after the contest is a necessary part of the sport.” 

Janus tried to collaborate with other pro eaters to share and track their health to better understand the effects of competing, but he couldn’t rally their interest. He’s now a foreign service officer in Mexico City in good health. Most of his former competitors say they’re healthy, too, but he “didn’t want to continue and realize I made a mistake.”  

Speed-eaters may develop other illnesses associated with unhealthy diets, such as heart disease and diabetes. The American Medical Association has recognized speed-eating as an unhealthy practice. But Sudo and Wehry are trim and muscular. Their weights spike during contests but, afterward, they eat less than normal to recover their health. (Another incentive for fasting beforehand or after: belly fat can block the stomach’s expansion, some competitive eaters have found.) Wehry says he drops about 20 pounds in just a few days after contests. They say they avoid regurgitating food following competition. So do many other pro competitors.

Outside of competition, Sudo and Wehry exercise daily and eat nutritiously. Wehry estimates that 70% of his calories per year are highly nutritious; training and contests account for only 30%. His blood pressure is slightly elevated, but his cholesterol has actually improved since he started competing, he says. Sudo’s doctor has given her a clean bill of health. She gave birth without any complication at age 35. Even with the contests, “we still have a healthier lifestyle than 95% of the population,” says Wehry, a former competitive bodybuilder.

Another speed-eating couple, Rich and Carlene LeFevre, are longevity role models. After competing since the mid-80s, the LeFevres have reached old age in good health, Sudo says. (Rich is 80 years old.)

Can these speed demons eat their 9.25 cakes in eight minutes and have their health, too? Perhaps with the right genetics and behavior strategies, Melanson says. “You can’t assume it’s going to work for the general population.” Research suggests that other extreme competitors, ultramarathoners, are faring better than some scientists had expected, with many of them living into their mid-80s, Smoliga notes.

In addition to training as a dental hygienist, Sudo enjoys speed-eating for the thrill of competition and “putting on a good show.” At the same time, she and Wehry want long lives to watch their son grow up and meet their grandkids. “I’m going to do everything I can to stick around for a while,” Sudo says.