What causes a full feeling after eating a small amount of food?

A full feeling after eating a small amount of food can be caused by several factors, including the sensitivity of the stomach and the release of hormones that signal satiety. The stomach's stretch receptors may react strongly to even a small volume of food, especially if it's rich in fiber or fat. Additionally, psychological factors, such as stress or anxiety, can also influence perceptions of fullness. Certain medical conditions, like gastroparesis, can further contribute to this sensation by slowing down gastric emptying.