Another thing I've found really helpful in dining out is visualization and mental practice.
So you take the excellent advice to look up nutritional values for items you might order. (If you are going to a restaurant that doesn't have their info online, you can go to www.calorieking.com
. If they don't have that specific restaurant, you can at least find typical values for that type of food.)
Next, you spend some quiet time mentally rehearsing what will happen at the restaurant. You'll look at the menu (or not, because you already know what you're going to order, right?). You'll avoid the things you know you shouldn't have and zero in on the likely choices. You'll ask the waiter any relevant questions: "How is that prepared? Can I get a small salad instead of the potatoes?" etc. You'll place your order FIRST -- so you won't be swayed by what other people order. You'll order with a friendly smile, with all needed special requests: "Dressing on the side, no sauce on the fish, very little oil, please. And can you bring a to-go box with the entree?" You'll avoid the bread basket or other munchies. You'll pass on the alcohol. When the food arrives, you will portion out what will constitute an adequate serving and put the rest in the go box. You'll enjoy your meal, enjoying the company, eating slowly, giving your mind and body time to register the food you're eating.
See yourself making good choices. See yourself doing what you need to do to control your meal. Practice, practice, practice. By the time you get to the restaurant, it'll be old hat and comfortable rather than new and scary and full of temptation.