Can you keep cooked food warm for eight hours?

It depends on the food you want to keep warm. As with all food keeping it warm will eventually affect the quality of the food. Vegetables, meats and the like can be kept warm for many hours without spoiling. You need to keep a watch on food, as it may dry out or get sodden and go mushy. Keep foods covered to help with moisture retention of meats and to prevent the leeching of juiceds onto other foods. All food should be kept at 63C/145F to prevent bacteria growth in food whilst keeping it warm.