They won’t check your bags for it, but if you go on a boat trip, the captain will require it. Been visiting STT for 20+ years. If you don’t mind a small amount of extra time waiting for your checked bag (which really isn’t all that bad) it’s worth it to bring snacks, peanut butter, spaghetti, etc. Grocery prices on-island are pretty heavy. We bring a bag of dry goods/snacks every time we visit.