I've been doing the 5:2 diet since mid January (with one week missed as I was away) so far 10lbs off and on my non fasting days it's really had a positive on my appetite.
As exercise is difficult with the RA (and some of the meds don't help on weight side of things) I'm really pleased how its going. It may be a combination of the weight loss and the diet but RA seems to be behaving a lot better too.
Keep up the great work folks