Is Buffet system of eating in programmes permissible to any extent or it is totally haram in islam? Please describe in detail with all the possible references.

All perfect praise be to Allaah, The Lord of the Worlds. I testify that there is none worthy of worship except Allaah, and that Muhammad is His slave and Messenger.

What is called "open buffet" in a way that a man pays a given amount of money and then he enters and eats all he can from whichever food he wishes, is an issue about which Shaykh Ibn ‘Uthaymeen was asked: “There are some restaurants that say: 'Pay 20 Riyals and eat as much as you can' what is your opinion on this issue?” He answered: “It appears that this is usually tolerated among people, as the size of an average meal is known, and this is something that is tolerated according to the customs. However, if a person knows that he eats a lot (an extraordinary amount of food), then he must mention this to the owner of the restaurant because people vary in this regard.” 

Allaah Knows best.