Morbid obesity is anything over a BMI of 40 (between 30 and 40 is just regular obesity).
I have such great empathy for people who do this to themselves, for the people that enable this, and the great changes people have to undergo to be able to understand what they're doing. Almost all people (from what I've seen/read) that are morbidly obese have emotional attachments to food. To be able to break the cycle, you have to be able to almost detach your feeling towards the food (ie, feeling emotionally satiated). I empathize with this greatly. It's a horrible cycle of eating to make yourself feel better, feeling depressed because you just ate and then eating to relieve that distress.
What I really don't get are the parents that see their children go down this route and do nothing. I wonder how broken they are, or how much denial they are in to allow this to go on. On a message board I belong to, we were discussing whether parents should be criminally liable for their obese children. What are your thought?