" Also, milk does give us calcium, and calcium, along with magnesium and B vitamins, is involved in sleep regulation (while calcium deficiencies are sometimes associated with sleep problems). So although foods that contain calcium won't put us to sleep, there are key nutrients they include that provide the necessary building blocks for sleep. The same is true of foods that contain magnesium (such as nuts, seeds, leafy greens, and bananas), B6 (such as fish, beans, and poultry), and tryptophan (an amino acid found in foods like chickpeas, seaweed, egg whites, pumpkin seeds, halibut, and most famously, turkey). Another food that may help us sleep is cherries, which are rich in melatonin. A 2014 study from Louisiana State University found that participants who drank a glass of tart cherry juice twice a day for two weeks slept an average of eighty-five minutes more each night than those who drank the placebo. "
― Arianna Huffington , The Sleep Revolution: Transforming Your Life, One Night at a Time