Refined food is simply unnatural, highly processed slop that is generally very unhealthy. Refined food is the term for food that has gone through many processes to modify basic foods to improve generally the shelf life (time before it goes rotten), but also to change the way of storage (ie. longlife milk and juice that don't need refrigeration) or to enhance flavour, colour etc. The additives and processes usually make the food very bad for you. Anybody can eat it, it's not just for 'refined' people, but it isn't good for anybody. For examples of foods that are refined (processed) carbohydrates, see the page link, further down this page, listed under Related Questions.