Friday is the Fourth of July, so if you can’t dream up a new way to celebrate our nation’s birth, why not consider attending an event that has been held each year since 1916. What, you ask, might that be? Nathan’s Famous Fourth of July International Hot Dog-Eating Contest.

During the months of April, May, and June, a 13-event qualifying circuit was conducted throughout the U.S. in order to bring together the compelling talents of 16 men and 12 women who intend to compete in the finals. Before that snigger escapes your lips, let’s mention the prize money. This year’s winners will split a $40,000 purse. Earned, by the way, in just 10 minutes. Good work if you can get it. And what about glory? Last year an estimated 40,000 fans cheered on the proceedings.

This year, everyone expects a repeat of the past few years when winners and losers are tallied. Joey “Jaws” Chestnut managed to scarf down 69 hot dogs, complete with buns last year, while Sonya “the black widow” Thomas, who was off her game, inhaled 36 dogs. (She’s been known to eat 45 in competition.) Though the sprint to the finish may look fun, it can’t be easy when one of the key rules of the game is no vomiting. And don’t even think about cheating with the International Federation of Competitive Eating (IFOCE) watching.

So how do they do it — what goes on deep inside the bowels of these champs?

Since the average stomach comfortably holds a liter of food, Dr. Marc Levine of the University of Pennsylvania wanted to see what was happening inside the stomachs of a competitive eater during a speed-eating contest. So Levine and his team of researchers X-rayed the stomachs of a competitive eater and a normal person as they both ate hot dogs.  What did they see? The competitive eaters' stomach appeared to be able to expand more than those of average people, forming “an enormous flaccid sac capable of accommodating huge amounts of food," they wrote in their 2007 study.  

“I guess I'm fortunate in that my body will have digested what I eat within 8 to 12 hours,” writes Thomas on her website, “By the next day — or late that same day — I'm usually ‘good to go.’” Well, OK!

A single Nathan's hotdog is 300 calories, give or take. Chestnut and Thomas, then, consume within 10 minutes 20,700 and 13,500 calories, respectively. With daily calorie recommendations ranging between 1,800 and 2,500 per day, this amounts to more than a few days’ worth of energy consumed in just minutes. (Burp.) Hot dogs also contain a lot of sodium, which can have killer effects on the body when consumed in high quantities, causing a person to feel faint.

Levine and his co-authors surmised, based on all the salt and calories, your average competitive eater would eventually develop morbid obesity, intractable nausea and vomiting, and gastroparesis (when the muscles inside the stomach no longer work). Someday, they may even require a gastrectomy — surgical removal of part of the stomach. "Despite its growing popularity, competitive speed eating is a potentially self-destructive form of behavior," wrote Levine and his co-authors.

Kill joy.