Anas (May Allah be pleased with him) reported: The Messenger of Allah (PBUH) said, "Eat Suhur (predawn meal). Surely, there is a blessing in Suhur."[Al-Bukhari and Muslim].
This Hadith tells us that Suhur is Masnun (Sunnah of the Prophet (PBUH)), even if one takes a small quantity of food. This meal is blessed and maintains one's energy and vitality during Saum. Against this, if a person goes to sleep after taking his dinner to save himself from the inconvenience of getting up before dawn or takes Suhur early will be, on one side, disobeying Messenger of Allah (PBUH) , while on the other side, he will be feeling hunger and thirst very early and very much as he himself has increased the period of fasting by not taking the Suhur. Subhan Allah! How the weaknesses of man have been taken into account in the teachings of Islam while suitable provision has been provided to overcome them!