Why does the stomach produce more acid when you overeat?

Overeating does not cause the stomach to produce more acid. When someone eats too much food, the stomach distends and stretch receptors located on the stomach wall trigger the release of hormones that slow the emptying of the stomach into the small intestine. Gastric acid secretion continues at a normal rate so the excessive undigested food in the stomach can eventually be moved into the small intestine.