How authentic are the hadiths: "The root of every disease is coldness," "The stomach is the home of all illness," and "We are a people who do not eat until we are hungry, and if we eat, we are not full"?

The first Hadith, "The root of every illness is the burdah (cold/chills)," is very weak and denounced (munkar), and it is not authentically attributed to the Prophet, peace and blessings be upon him. As for the saying, "The stomach is the home of all illness," it is not a prophetic Hadith, but rather one of the sayings of physicians. It is said that the first to utter it was Al-Harith bin Kaladah. The other Hadith was declared weak by Sheikh Ibn Baz.