Several fruits and vegetables contain tryptophan, which is a building block to creating mood-boosting serotonin. So if we consume produce rich in tryptophan, our bodies can make more serotonin. Plantains, pineapple, bananas, kiwi fruit, plums, and tomatoes contain high amounts of tryptophan. Moderate amounts can be found in avocados, dates, grapefruit, cantaloupe, and more. Eat a variety of fruits and vegetables every day to get the best health benefits.