When we talk about tryptophan foods, it is usually in reference to turkey and the post-Thanksgiving coma it induces. Tryptophan is one of 8 essential amino acids that our bodies need. The body uses tryptophan to produce serotonin, which can then used to make melatonin, our “sleep hormone.” But there is absolutely no need to eat turkey to get tryptophan. In fact, there are many plant sources of tryptophan which have much more of the amino acid than turkey.