Canned foods and tomatoes: These foods contain large amounts of sodium, which provokes fluid retention in the body. 2. Wheat bread: Gluten in bread and white flour products could be one of the leading causes of under-eye swelling.  3. Sugar and hot peppers: Hot peppers, like tomatoes, contain solanine and capsaicin, which causes burning and swelling of tissues. Sugar causes inflammation throughout the body, but its consumption is especially noticeable under the eyes.