Grand Lido sections lacks it's own restaurant to eat au natural. With that said. at the outdoor area where you layout nude or swim or drink... they serve lunch there so you can eat nude but you'll eat on your beach lounger. For breakfast there is an area you can eat outside with clothing on but this location has limited food choices. we chose to walk to the buffet which we enjoyed. getting dinner reservation was easy and guaranteed. Since you're a GL guest you are top tier and can go wherever you want, they'll make room for you.
The butler service for us was TERRIBLE- we hope they were fired.. Lunch service was slow and below expectation. The area was not kept as clean as expected for a top tier room rate. drinks were very weak from one bartender and better from a different bartender so it's a hit & miss. There is no "beach" @ GL but access to the ocean via imbedded ladder in the wall. the other section of the property you can visit has beach ears with clothing required. At GL you'll need to reserve your chair with your towel if you expect to pick your location to layout. I think the GL has 34 rooms, so it's a small 'property'.
hope this helped.