Anorexia nervosa is a condition full of irony and paradox. Perhaps the most enigmatic of these is that professionals tend to hold the same morbid preoccupation with weight, BMI and targets as do our patients. In this article we outline why we believe that an over-emphasis on weight/BMI and targets is inappropriate, misleading and potentially harmful. Although this view is not always greeted with enormous enthusiasm by some, others are relieved that this particular ‘holy cow’ is at last being challenged. It is important that we should all have an open mind to the possibility that one of the main tenets of our practice may actually be unhelpful. Some ancient wisdom is drawn upon to support this view. Copyright © 2009 John Wiley & Sons, Ltd and Eating Disorders Association.