Who knew that competitive eating was an international sport? Or that people who eat unthinkable amounts of food in restaurants are the subject of reality TV programs? It was only after watching an episode of "Man v. Food," where the host devours enormous quantities of food in a limited timeframe, that the world of competitive overeating was revealed to me. I was at the gym at the time. Prior to this, the only competitive overeating I had seen was at a dinner whose guests included several teenage boys.
The star of "Man v. Food," goes to various restaurants in the country to take on the challenge of consuming a huge amount of a menu offering within a timed segment. I watched this episode in horror, as the challenge was to consume a thick milkshake in a container about the size of a grain silo and also eat what looked like a Reuben sandwich somewhat bigger and wider than his head. This had to be done in an hour and, sorry to say this, but he was not allowed to go to the bathroom during this time. Of course, he met the challenge, and although I continued to exercise longer than I had planned to see if his stomach would burst, he was able to walk away from the table more or less upright.
His eating feats are not unique. Several animal species consume prey larger than themselves. Predatory animals must be able to eat their kill before others arrive, even if it means putting enormous amounts of food into their stomachs as quickly as possible.
These days, non-predatory humans are competing for large amounts of money by participating in the "sport" of speed eating. The first such competition was held at Nathan's in Coney Island, N.Y. in 1916. But now, almost 100 years later, speed eating has become so widespread and popular, it is overseen by the International Federation of Competitive Eating, which monitors the age of the participants and hazards of eating (and not chewing) vast quantities of food. The foods in play, as it were, are not limited to hot dogs. For example, there is a Wing Bowl contest in Philadelphia that features the consumption of buffalo-style chicken wings, and one of the world record holders, a gentleman named Kobayashi, has topped his competitors in the consumption of not only hot dogs, but hamburgers, brats, rice balls and cow brain. 
Much of this information comes from an extremely well-written and funny article published by Marc Levine and colleagues in the September 2007 issue of the American Journal of Roentgenology.  They, like many of us, wondered how ordinary humans could eat such large quantities of food, especially without damaging their entire gastrointestinal system. Where does the food go? Does it get dumped out of the stomach really quickly, so there is room for more, or does the stomach stretch like the body of the python swallowing a goat?
They were able to answer such questions by recruiting a champion speed eater who allowed the contents of his stomach to be tracked as he rapidly consumed a large number of hot dogs. An ordinary big eater was recruited as a control subject. Both men were normal in size; the competitive eater was slim, as was the big eater, although the latter was several inches taller and weighed proportionately more. Both men had flat stomachs, at least before the eating began.
Fluoroscopy was used to view the fate of the hot dogs. Each subject swallowed a small amount of barium, which coated the lining of the stomach. As the pieces of hot dogs entered the stomach, they made little depressions in the coating of the barium, just as your footprints would make a depression if you walked on wet cement.
The big eater turned out to be a wimp compared to the competitive eater -- he said he felt sick and gave up after only seven hot dogs. The competitor downed 36 hot dogs in 10 minutes and would have continued eating but was stopped by the researchers who feared he might damage his stomach.
So where did the hot dogs go? Nowhere. They stayed in the stomachs of both eaters. Unlike the control subject, the eating athlete was able to eat as much as he did because his stomach, like that of a python, stretched enormously to accept and hold the food. According to the researcher's observations, the small pouch that had been the stomach was now distended into a " ... massive, food-filled sac ... " that filled most of the abdominal cavity (think pregnant women).  And despite its size, the competitive eater said he did not feel full -- indeed, he never felt full.
His stomach did return to its normal size after several days because he monitored his food intake very carefully and limited his meals to very small amounts of low-fat foods. Fullness was useless as a signal to make him stop eating, either during a competition or when eating a normal diet. Willpower to stop eating after his measured meals were consumed was what allowed him to maintain a normal weight.
This led me to ask, might the rapid enlargement of the competitor's stomach during an eating competition be a model for what happens to people who frequently overeat massive quantities of food? Is it possible that the reason people who are obese find it so hard to diet is that their chronically-stretched stomachs never feel full? Normally, as nerve endings on the wall of the stomach become stretched, they signal the brain that eating better stop soon because discomfort will slide into pain, as evidenced by the control subject. The competitor felt no such signal. Perhaps people used to ingesting enormous quantities of food daily feel no such signals because their stomachs are so stretched.
Perhaps this is why surgery that reduces the size of the stomach so effectively produces significant weight loss. The stomach signals to stop eating are restored and fullness is felt after only tiny quantities of food are eaten. But just as joint replacement surgery seems to be the fate of aging professional and amateur athletes, will stomach reduction surgery be the fate of all the others who are so actively participating in the sport of excessive eating? Wouldn't it be a better idea for them to take their competitive streak to the gym, rather than to a hot dog stand?
Follow Judith J. Wurtman, PhD on Twitter: www.twitter.com/stopmed_wt_gain