Top 5 food mark-ups where restaurants make huge profits

Have you ever wondered why sometimes your server looks slightly annoyed when you tell them you're having water with your meal? Or that she is more worried about the level in your wine glass than you? Or why many restaurants went to free re-fills on soda a few years back without batting an eye?

There are logical answers to all of these questions, centered on one thing and one thing only: money. As you might expect, restaurants do not make the same amount from every single item they sell. Some items boast huge profit margins -- so logically, they will try to lure you to order the ones that rake in the most cash.

What follows is my list of the top "money makers" in the restaurant industry -- good information that might shed light on a few things the next time you dine out. The list provides a neat insider's view into how restaurants are run; for more applicable ways to save money, check out these other tips to save money while eating out, as well as great restaurant discount resources such as the Entertainment Book.