Ruby is such a good show because at it's heart is a whole person, rather than a gimmick, and the show follows her attempt to overcome a life-threatening obstacle by taking responsibility for herself and dealing with her feelings; to keep pushing forward, despite setbacks and self-doubt; and to learn to trust and rely on others for support and guidance.
Each episode shows people overcoming fears and taking risks by telling the truth. In fact, we watch Ruby and all the others, even her doctors, struggle against their own limitations with an openness and depth unusual to television.
This is the real stuff of what it is to be human, and one of the surest survival plans available to any of us. Luckily, the editors preserve the honesty, insight and charm of this group so events seem natural rather than set up.
An earlier comment's inaccuracies may be based on a hasty impression or misperception:
--The life-threatening dangers that motivate her struggle are noted in each episode, and her fear and her doctors' warnings are not glossed over or minimized. The weight issue is never "a ticking time bomb that is cheerfully ignored." --The episode where an old boyfriend visits is shown in perspective for exactly what it is and contrasts sharply to the love and support of the real people in Ruby's life like Jeff Parsons. We watch Ruby forcing herself to see this for what it is and triumph by overcoming this distraction and staying on course. --There is a great deal of medical information, in fact much of the series follows Ruby's work with each individual in her medical support team including a physician, a psychiatrist, dietician, and two fitness experts. It is hard to comprehend the comment that "no medical facts or helpful advice is proffered".
This show deserves a full viewing.