Here’s another toddler favourite that’s packed with amino acid tryptophan that’ll help him sleep. For the biggest sleep-boost, serve it with healthy wholewheat carbs. “This helps your youngster’s body convert the tryptophan into the sleep-supporting hormone serotonin,” says Lucy. “Carbohydrates also increase insulin production, and that lowers the levels of other amino acids in his body. Without the competition from those other amino acids, more tryptophan can get into your toddler’s brain.” Jacket potato with cheese, cheese grated on top of wholewheat pasta, or cheese on toast are all great combinations.