Whole grain cereals or whole grain bread contains tryptophan, an essential amino acid and a building block for two sleep regulating hormones, serotonin and melatonin. According to research, increasing serotonin levels stimulates sleep. In addition, whole grain products serves as good night snack as it provides the body with nutrients yet does not lead to a surge in blood sugar like refined grains would. Snacking on a handful of whole wheat cereal at night will help negate an increase in blood sugar that you would experience if you eat a cereal with sugar.
Drinking a glass of warm milk before bed sends you off to sleep because a warm liquid helps raise the body temperature and brings on sleep. Furthermore, milk also contains tryptophan which converts into sleep inducing hormones,serotonin and melatonin. The calcium present in milk also serve to facilitate the production of melatonin.