There is a lack of evidence in support of nutrition or food affecting one’s sleep, although well-balanced regular meals and a regular exercise regimen are recommended as part of good sleep hygiene (sleep habits).
Some studies have linked specific types of food and beverages with sleep, but the data are mixed. For example, warm milk has been discussed as conducive to sleep, due to its abundance of tryptophan, which is converted to serotonin, a brain chemical that has been linked to promoting sleep. However, the evidence for this is not conclusive.
Similarly, intake of carbohydrates has been linked to promoting alertness, while protein consumption has been linked to sleep; however, evidence for these types of food in relationship to alertness/sleep is also debatable.
There are some substances that one should consume with caution, particularly if the individual has difficulty falling or staying asleep, such as chocolate, cola drinks, tea, and coffee, all of which contain varying amounts of caffeine.