It is narrated from Sayyiduna Ibn Abbas (may Allah be pleased with them both) that the Prophet (peace and blessings be upon him) would spend several consecutive nights hungry, and his (peace and blessings be upon him) family would find no evening meal. (Sayyiduna Ibn Abbas, may Allah be pleased with them both) said: And their bread was mostly barley bread.
Hadith Referenceالمعجم الكبير للطبراني / باب العين / 11850