It takes time for you body to know that you're full. You may not want dessert after two leisurely courses. Choose foods that are grilled, broiled, roasted, steamed, poached, baked or stir-fried rather than those that are breaded, fried, creamed, buttery, in gravy, scalloped or au gratin. Instead of fatty desserts, try fruit sorbets or a frothy cappuccino to end the meal. Think ethnic, especially Asian.
Asian cuisines can stretch a piece of protein from here to Beijing.
If you're going to a salad bar, put the dressing in a separate container and add judiciously. Better yet, stick your fork in the dressing before you stab the pieces of salad. Don't be timid about asking how a dish is prepared. It's your money - and your body. Call ahead to find out what the menu is like if the restaurant is unfamiliar to you.