Sayyiduna Amr bin al-As (may Allah be pleased with him) said that the Messenger of Allah (peace and blessings be upon him) said: "The difference between our fasting and the fasting of the People of the Book is eating the pre-dawn meal (suhur)."
Hadith Referenceالسنن الكبرى للبيهقي / كتاب الصيام / 8115