Snacks that are moderately rich in carbohydrates promote secretion of serotonin, also known as the sleep inducing hormone. Even melatonin rich food has the same effect. Thus, you can well understand the fact that, the food we consume at the end of the day has a direct effect on the hormones in the body. It's also important to note that, hot and spicy food causes disturbance in your sleep. Prefer having cold and light dishes before sleeping. Cold food has the ability to relax your brain, thereby making you feel sleepy instantly.