Sister into depression

My sister is morbidly obese. She struggled with her weight right from childhood. Now she is kind of depressed all the time. Doesn't go out much, she has no friends. We are really worried about her. She tried to change her ways of eating, but she says its beyond her control now. How can we help her. I read a post recently which said, certain De-addictions centers will be able to help in such cases. Is that so? I found one near us, ( http://www.bellwood.ca/eating-disorders/ ). Would like to get a second opinion, before we talk to them.