Certain fish and sea creatures contain sleep-inducing tryptophan, including shrimp, cod, tuna, and halibut. But since not all seafood choices are healthy for us (some are high in contaminants) or for the planet (many are overfished, or methods for catching them kill other species), stick to catches like Pacific cod from Alaska or pole-caught Albacore tuna from the U.S. or British Columbia.