Why do people stop eating when they feel unwell or worried about something?

When we feel worried or unwell, our bodies release epinephrine (adrenaline), which affects the digestive system. Blood flow to the digestive tract is reduced, which can lead to a feeling of indigestion or a "stomach knot." Furthermore, the increase in adrenaline also interferes with other hormones that regulate appetite, in addition to releasing glucose from the liver. This glucose signals to our body that we have enough energy, thus reducing the sensation of hunger. Besides adrenaline, emotional distress related to worry can trigger a response of suppressing or withholding food, either because the need for food is not perceived or because it is a previously learned behavior: "when I'm worried, I don't eat."