I cannot stress the importance of this in casual conversations with small fats/fats and fat-sympathisers.  When you state "yeh, well Noreen is morbidly obese..." and people gasp, they have no reply to "she is way over 20 stone and is 5 foot 5, the MEDICAL TERM - NOT MY TERM -THE TERM USED BY DOCTORS AND SCIENTISTS AND SHIT -  is morbidly obese...anyway....so she broke the chair in mums conservatory yesterday..."