Below is my favourite Hadith, which was re-enforced when I learn't both Chinese and Islamic Medicine. Nothing is more true than the below.
“The son of Adam cannot fill a vessel worse than his Stomach, as it is enough for him to take a few bites to straighten his back. If he cannot do it, then he may fill it with a third of his food, a third of his drink, and a third of his breath.”
Source for Muslims: Sunan al-Tirmidhī 2380
Source for Chinese Medicine patients: The Yellow Emperor
"When the diet is wrong, medicine is of no use. When the diet is correct, medicine is of no need" Ayurvedic Proverb.
"The secret of living well and longer is eat half, walk double, laugh triple and without measure" Tibetan Proverb.