Here are some sample menus...I have to say, having been on many =X= cruises, the food is wonderful. There was a "rough patch" about a year ago, but I think it has improved.
If you will be on a Millennium class ship, the Aqua Spa Cafe has great menu options that are usually low fat or low carb / low sodium. The main dining rooms have their own menu, as does the specialty restaurants. Here's a sample:
Main Dining Room:
Menus from the Infinity (we'll be on next month!!!) Main Dining Room and the Specialty Restaurant:
Typical Cabin Service Menu:
Here's a sample menu from the new Solstice and Equinox:
In addition to the main dining room (restaurant), there is a casual dining restaurant on M-Class ships, as well as a pizza and sushi bar and grill which serves up BBQ, etc.