The Gallon Challenge is a contest in which people chug a gallon of milk, though it has evolved into a competition where people attempt to out-drink each other within a set period of time. They have 60 minutes to drink at least a full gallon of milk. The challenge can also be done with other liquids besides milk.
Although CEO Peter Ubriaco claims he started the first milk chugging contest in 2000, news reports indicate that milk-chugging contests occurred in 1997. Ubriaco turned the Gallon Challenge into a nonprofit organization that raised donations for food and health-related programs. The difficulty of the Gallon Challenge stems from the physical limits of the human stomach, which can generally only stretch to hold half a gallon. The supposed impossibility of the milk challenge combined with the media coverage attracts college students looking to celebrate and celebrities looking for a publicity stunt.
While the Gallon Challenge can be undertaken with water, this risks water poisoning. In addition, milk is harder to drink in large quantities than water because it is filled with fats and proteins that prevent the stomach from emptying into the small intestine, forcing the stomach to hold more liquid at a time.