It is narrated from Sayyidah Umm Salamah (may Allah be pleased with her) that when the Prophet (peace and blessings be upon him) wished to sleep while in a state of janabah, he would perform ablution like the ablution for prayer, and when he wished to eat, he would wash his hands and then eat.
Hadith Referenceالمعجم الكبير للطبراني / مسند النساء / 20282