Sayyiduna al-Fuja' al-Amiri (may Allah be pleased with him) came to the Prophet (peace and blessings be upon him) and said: "What of carrion is lawful for us?" He said: "What is your food?" We said: "Drinking one cup in the morning and one cup in the evening." He (peace and blessings be upon him) said: "That, by my father, is hunger." So he (peace and blessings be upon him) made carrion lawful for them in this state. This shows that he permitted them to eat carrion along with the morning and evening (drink) that only keeps them alive, when these do not nourish the body or fully satisfy hunger.
The authenticity of these hadiths is open to question; the hadith of Jabir bin Samurah is the most authentic of them.
Hadith Referenceالسنن الكبرى للبيهقي / كتاب الضحايا / 19640