They do bring lunch over from the mainland and it's pretty good. Be cautious of the wind though, we were there one day when it was only a yellow flag and the wind was blowing the salad off my plate. Still wasn't worth getting dressed and going back to eat though! lol
The lunch on the island is nice. There is always fish, chicken, vegetables and salad, usually some cookies or other dessert. It's set up buffet style about noon for a couple of hours. You can always run back to the mainland for something from the grill or whatever, it only takes a few minutes, but I hate putting clothes on. My husband likes to get a burger and has done that a few times.