Weight loss and more importantly, weight maintenance, is all about personality change. A sufficient personality change to bring about recovery. Along with personality change, or likely the cause of personality change, are changes in the beliefs and values, including what we consider to be food, when and how we eat, and the like.
It is the personality change that must occur to give the fixity of personality required to maintain a weight loss. That is what I now consider to be the missing ingredient in most weight loss schemes, but what do I know.