I have fed them and they really increased in size quickly. I have cleaner shrimp and serpent stars and nassarius snails that go nuts when I drop in pellet food at night, but the rics do swallow what they can if they aren't too disturbed.
I've not fed mine in a good month, but they are still looking pretty good overall. I just hate fighting off the crew just to get a few crumbs down their little throats.