10 foods to avoid. There are certain foods which trigger the stomach to produce excess acid when consumed. This acid is what causes the burning pain that is usually associated with ulcers. These acid-producing foods, along with fatty foods, should generally be avoided in order to avoid discomfort. Foods to avoid include fatty meats, fried food, snacks that are high in fat like butter popcorn or chips, raw vegetables, citrus juices and fruits, caffeinated drinks, milk, spicy foods, chocolate and alcohol.