Wherever I go there is usually some sort of grilled fish on the menu (I'm in New Orleans) so I usually get that with no sauce or butter on it, and most places will just steam some broccoli for you even if it's not on the menu.
Italian places always have chicken dishes, which means they can grill you some chicken if you ask.
Chinese places are tricky. Almost everything is loaded with oil, and white rice is a bad idea if you are watching carbs. And those fried wontons, man I love them, but is anything more unhealthy than those

? I usually get some shrimp in garlic sauce or just use that as a cheat meal and get whatever I want.
Mexican is easy for me, I get chicken fajitas and give the tortillas to my kids, and pile on the peppers and salsa

. Cebollitas are grilled green onions, and I get a side of those to add to whatever I am eating.
My favorite salad is just plain spinach with olive oil and balsamic vinegar.
The bottom line is you are going to have to order specially prepared items, usually off the menu. Nobody said it was going to be easy. If it was easy, everyone would have washboard abs
