The empty stomach of an adult is roughly equivalent to a 0.5-liter can of soda and can stretch to the size of a 2-liter bottle, with some even expanding to 4 liters.
After enjoying a hearty meal, eaters often feel their stomachs larger and their clothes tighter. So, how much can the stomach expand at its maximum?
The empty stomach of an adult is like a large folding bag, equivalent to a 0.5-liter can of soda, and during a meal, it can grow to the size of a 2-liter plastic bottle, according to Arthur Beyder, an associate professor of medicine and physiology at the Mayo Clinic.
“It can expand four times or more,” Beyder stated. For most adults, this means the stomach can hold 1 to 2 liters of food and liquid, depending on age and body size. In special cases, such as with competitive eaters, the stomach can stretch to accommodate 4 liters.
The stomach can expand four times when full. (Photo: New York Post).
A 2018 study published in the journal Gastroenterology documented the case of a competitive eater who required emergency care after overeating to the point where their stomach expanded, compressing the pancreas and displacing the intestines. After five days in the hospital, the individual was able to pass gas and have a bowel movement, qualifying them for discharge.
Overeating also commonly occurs at parties, when people are stressed, or when they are distracted by watching TV, according to Benjamin Levy, a gastroenterology specialist at the University of Chicago. “They get distracted, and before they realize it, they’ve eaten too much,” he explained.
Hunger is stimulated by the hormone ghrelin. This hormone is primarily secreted by the stomach, but also by the brain, small intestine, and pancreas, according to the Cleveland Clinic. Ghrelin is released when the stomach is empty to signal the brain that it’s time to eat.
When a person begins to eat, food travels down the esophagus into the stomach. Folds known as rugae allow the stomach to expand to accommodate food and liquid. As food enters, the stomach secretes hydrochloric acid and digestive enzymes. This organ also starts to contract, breaking down the food into smaller pieces for nutrient absorption later in the small intestine.
The stomach is made of smooth muscle, which can tighten and hold contractions for extended periods, even after it has expanded. This allows the stomach to create more space for additional food.
“It’s similar to a rubber band; you stretch it, and it bounces back,” Beyder noted. This phenomenon is called muscle tone, which helps regulate the stomach’s tension levels. Stomach tension is communicated to the brain via the vagus nerve, which runs from the intestines to the brain, according to the Cleveland Clinic. This is just one way the stomach informs the brain about fullness.
Additionally, there are hormonal changes that signal the brain when to stop eating. Ghrelin levels decrease, while other hormones signal satiety to the brain and reduce appetite. If someone overeats, they may have ignored these signals, or eaten so quickly that the hormones couldn’t relay the message to the brain.
The key is to eat slowly, Levy advised. “Sit there and talk for 15 minutes before going back for more food,” he suggested. Although the stomach is designed to stretch and hold large amounts of food, people tend to feel better if they avoid overeating, Levy emphasized.
However, if someone does overeat, there are several things they can do to alleviate discomfort. First, they should avoid lying down, as this can cause acid reflux. Instead, Levy recommends going for a walk. This action helps stimulate digestion and encourages food to move through the digestive system.
