I eat lots of fish when I'm on vacation. I order the grilled fish and douse it in lemon (no toppings) wherever I am, and choose sensible sides! Also drink TONS of water at every meal and you'll feel full, and you'll probably be walking around tons so it's just a good idea to stay super hydrated. My fam loves to order appetizers, salads, entrees, dessert...so if I participate in any of that, I make sure to only "try" a bite of stuff, but in general I find it's better to just stick to my entree. Do not fill up on the bread either! I used to LOVE bread at restaurants but now I just see it as a meal-ruiner, and calorie-taker-upper. No toppings, no bread, lots of water, but make sure you get a couple bites of dessert, because you're on vacation!