Pro Living Keto What not to eat with a stomachache Although the pain in the stomach decreases appetite, it is important to make small and frequent meals, every 3 hours, since staying a long time without eating can cause the stomach to release acid when it is empty, making the pain worse.When there is pain in the stomach it is not recommended to eat foods high in fat, or to consume foods that are irritating to the gastric mucosa and can aggravate any inflammation in the stomach such as: