Well I've been feeding my girl as if she is cushings and laminitic just to be on the safe side. I can tell you no rice bran, no grain whatsoever. beet pulp and alfalfa for weight.
I highly recommend Feedxl.com to figure out what to feed. You check the diseases box and it will highlight things in red that you shouldn't feed. Very helpful and it ensures you are feeding a balanced diet.
What I have found to work is alfalfa pellets since I can't get alfalfa hay with about 2 oz of wheat germ oil per day. Walkinthewalk can help you so much more, she has delt with all of this and has done so much research.