Americans love eating out -- and that affection for restaurant food is growing.

Restaurant industry sales were $379 billion in 2000, reaching an estimated $558 billion in 2008, according to the National Restaurant Assn. But there's a price to pay beyond the tab -- thicker waistlines. Many restaurant items are laden with fat and calories, far more than most people would estimate.

But eating out doesn't have to be unhealthful. More restaurants are offering choices lower in fat and calories, and many are posting nutritional information for some or all of their dishes online so that diners can get the low-down before facing temptation.

The following are comparisons of similar dishes at popular chain restaurants. One item is on the high end of calories and fat, the other low, showing the difference a couple of tablespoons of mayonnaise or handful of cheese can make:

Chipotle

Meals in which consumers choose the ingredients offer the opportunity to eat smart -- or pig out. Both of these options started with a flour tortilla, cheese, lettuce and tomato salsa.

Pizza Hut

There's no reason to avoid favorite foods such as pizza, but toppings can turn a reasonable choice into a nutritional disaster. Notice the fat difference here.

Panda Express

Chicken is chicken -- not. How a dish is prepared can completely alter calories and fat. The mushroom chicken is a nutritional star compared with the popular orange chicken.

P.F. Chang's China Bistro

Two shrimp dishes, two very different calorie counts. The Crispy Honey Shrimp is lightly battered and quick-fried, while the Cantonese Shrimp is stir-fried.

Most restaurants are used to accommodating diners' requests for sauces and dressings on the side. P.F. Chang's goes one further: Ask for dishes "stock velveted" and they'll be cooked in vegetable stock instead of oil, a common Chinese cooking technique that cuts way down on fat and calories. At other restaurants, ask if the kitchen can lighten foods by cooking them in little or no oil or butter.

Rubio's Fresh Mexican Grill

Most restaurants tout extra, grande, super-size or especial meals, but more food and more flavor usually mean more calories and fat.

Starbucks

Not all breakfast breads are created equal. It's a good bet that muffins, sweet rolls and coffee cakes are going to be loaded with calories and fat.

But don't be fooled by reduced-fat items -- they can be fattening too. Starbucks' reduced-fat Strawberries and Crème Coffee Cake, for example, has 330 calories and 9 grams of fat.

McDonald's, Wendy's and KFC

Grilled foods are usually lower in fat and calories than fried foods. In these wraps, grilled versus fried counts for about a 60- to 80-calorie difference and saves several fat grams. Not a huge difference, but most people don't eat just one, so that calorie saving adds up.

Denny's

Breakfast is important, but some meals will ruin the day before it's begun. Here, the French Toast Slam provides more than half of the calories most people need in one day.

Watching when you eat is important too. Denny's is starting a late-night promotion with rock music, waiters in blue jeans and foods like the Sweet Ride Nachos -- tortilla chips, cinnamon sugar, fruit, hot fudge and whipped cream.

In-N-Out Burger

The Protein Style burger at In-N-Out has less than half the fat and calories of the Double-Double, which sports two beef patties and two slices of cheese. That "secret sauce" on most fast-food hamburgers has a mayonnaise base, so it's better to stick with ketchup and mustard.