If we finished eating our body act for several hours with these foods. It is to breaking our foods and absorbing to body. Sleep time is the leisure time of the body. All of the body organs become refresh during this sleep. Energy will gather into the body again. If our body active with digesting food in our sleep time, the purpose of the sleep will not complete there. There is no actual leisure of the sleep there. Therefore you have to complete taking foods atleast 2-3 hours before go to sleep.
You know there is a biological clock and our body acts to this clock. Get up at the time, washing face, go to sleep and it is because of this biological clock. If we forget our body automatically doing those at right time. Biological clock has chosen a best time to sleep. It is between 10 p.m. to 2 a.m. If someone does not use these valuable 4 hours to sleep it can affect to the rhythm of life. Therefore the quality and importance of the sleep may reduce. It also cause to the daytime sleepiness.