Sumo wrestlers eat chanko-nabe every day to build up strength. Nabe means "Pot" (or a meal simmered in a pot); chanko is the meal eaten by sumo wrestlers. At the sumo stable—the place where wrestlers live and train—there is no hard-and-fast rule about what goes into the pot. Common ingredients are chicken, tofu, and vegetables like Welsh onions and Chinese cabbage, all cooked in a seasoned soup stock.

Japanese cuisine offers a variety of one-pot meals served with rice. Soup stock is heated in a pot at the dining table. Previously cut ingredients, generally vegetables, fish and/or meat, are simmered and eaten around the table. The Japanese enjoy the camaraderie that comes from gathering around a nabe with family members or good friends, especially when it is cold outside.

There are a number of explanations for the word chanko. According to one theory, the word originated at the end of the 19th century, when an aging retired wrestler took on the job of cooking every day at a sumo stable in Tokyo. The slang word for "dad" in Tokyo's working-class district is chan, so the old guy's pot-simmered meals were dubbed chanko-nabe.

Sumo wrestlers start their day with a long training session. After grappling, colliding and throwing each other around, expending plenty of energy, they are ready for a hearty meal that is both breakfast and lunch. One job of a sumo wrestler is to eat a lot and gain extra strength. They eat lots of rice, and chanko-nabe, which has plenty of liquid, goes down well with the rice. The vegetables, fish and meat, plus the rice, offer a nutritional balance that is easy to digest. And the meal is easy to make and serve, because one big pot holds enough for the many wrestlers eating together. This explains how chanko-nabe became an essential part of the world of sumo.

Japan's first chanko-nabe restaurant was opened in 1937 by a retired sumo wrestler, in Tokyo's Ryogoku district. After World War II, chanko-nabe gradually spread among the general population as yet another pot dish.

One commonly used ingredient is chicken. This is because in the old days sumo wrestlers did not like eating the meat of four-legged animals—one way to lose a match is to put a hand on the ground (in other words, to assume the posture of a four-legged animal). This custom is no longer followed, and today many stables serve other meat as well.

Even so, chicken remains a relatively cheap, easy-to-buy choice. The meat is cut from whole chickens and the bones are used to make the soup stock. When flavored with soy sauce and other seasonings, the soup forms the basis for a simple, tasty meal. If you add minced chicken balls, the juices make the soup richer.

When cooking a one-pot meal at the table, it is common to drop in some ingredients, eat, and then drop in some more, sukiyaki-style. But when cooking chanko-nabe, you should simmer everything in the pot together, to bring out the flavor. For best results, start with food that takes longer to cook.

After you finish eating all of the ingredients, the next step is to add udon noodles or cooked rice, then finish everything to the last drop, savoring the thick soup.