Shama-il Tirmidhi Chapter 024, Hadith Number 003 (137).
lbn 'Abbaas Radiyallahu 'Anhu reports that: "Rasulullah Sallallahu 'Alayhi Wasallam and his family spent many consecutive nights without food, because there would be no supper. The bread of Rasulullah Sallallahu 'Alayhi Wasallam was mostly made of barley". (Sometimes bread made of wheat was also available).
Although there were among the Sahaabah Radiyallahu 'Anhum, a few who were wealthy, Sayyidina Rasulullah Sallailahu 'Alayhi Wasallam did not let anyone know, nor did his family members let anyone know, of their state.