You can just stick with your normal diet, only thing is you may find you have to eat more frequently.
As for the conversion, assuming your talking about serono serostim the typical kit includes 7x 6mg vials(18 IU). Each vial is reconstituted with 1ml/cc of sterile water or BAW. If your using a slin 1cc pin marked in 100 units take 100units divide by 18 and you get 5.5 uniter per IU. If 6mg = 18IU, then 1iu = 333mcg or .333mg