If you go to the individual food here on Alla then scroll through the posts, you'll find one form Crayola, I believe, that has the statistics.
So far the sushi's seem to be consistent about +20HP and +14% accuracy (rumored to be R.ACC too). Sole Sushi also add +STR, Squid is +DEX, and what I'm hearing is Bream is +VIT. This is heresay because I only use sole atm. I haven't had the gil or time to test the rest. I do, however, notice a HUGE ACC difference.