You're starting your lunch break, driving away from the office and you're craving a cheeseburger. Did you know you can cut hundreds of calories, simply by choosing one cheeseburger over another?

May not sound like much of a difference, but over time it can be. Did you know you can save as much as five hundred calories by choosing one turkey sandwich over another?

The information is all at your fingertips. It's available online at most restaurant web sites, and often at the restaurants themselves.

Kimra Hawk, a registered dietitian at Providence St. Vincent Medical Center advises, "know before you go." She adds, "it can fool even a professional with how many calories are in some of these sandwiches and foods."

Compare, for example, the Carl's Jr. "Famous Star" with cheese and the McDonald's "Quarter Pounder" with cheese. According to each restaurant's web site, the Carl's Jr. cheeseburger has 660 calories, the McD's has 510 calories.

Compare the Panera "Sierra Turkey" and Subway's "Double Meat Turkey Breast" and you'll find a calorie difference of about 500 calories.

Andrew Carlson, Media Relations for Panera, suggests "you can cut calories by asking that the cheese and the dressing be left off".

Hawk agrees. She says skipping the mayonnaise will save you at least 100 calories.

You can even save calories by choosing one Krispy Kreme donut over another. Choose the "Original Glazed" instead of the "Glazed Sour Cream" and you'll save 100 calories.

So what could saving that 100 calories mean long term? Hawk says, it means a lot. "So everyday, if you cut out 100 calories, in a year you can see 10pounds weight loss!"