Are Fast-Food Chain Salads Really Healthy?

June 5 -- Many fast-food chains are now offering salads on their menus, but before you applaud yourself for choosing fresh greens over a burger and fries, take a closer look at the salad ingredients.

Good Morning America's food editor, Sara Moulton, tested 30 salads from some of the largest national fast-food chains in the world, including McDonald's, Burger King, Wendy's, Subway and a smaller chain, Au Bon Pain.

In some cases, based on the fat and calorie count, diners would be better off choosing a burger, Moulton says.

Here are Moulton's findings:

McDonald's: McDonald's has launched an ad campaign touting its premium salads, but some of the ingredients deserve closer scrutiny.

"The good news first: McDonald's is trying," Moulton said. "They use great grape tomatoes and they have a few 'real greens' in the bunch, but on the whole, the salad is pure iceberg lettuce. Iceberg lettuce has zero nutrients and zero grams of fiber. Romaine lettuce, on the other hand, has 1 gram of fiber per six leaves, and 32 percent of your daily intake of vitamin C. "

At McDonald's you can choose from the following options as a top for the restaurant's basic salads: Bacon Ranch, Caesar or California Cobb, all of which come with either grilled or crispy fried chicken.

The Grilled Chicken Bacon Ranch Salad contains 270 calories and 13 grams of fat. With light balsamic vinaigrette dressing, it totals 360 calories and 21 grams of fat.

"The grilled chicken is too over-seasoned and salty," Moulton said. "The fried chicken is tasty, but if you have a California Cobb Salad with Crispy Chicken and ranch dressing it's a total of 670 calories and 53 grams of fat."

That is only 130 calories less than a Big Mac and small fries, which together contain 800 calories. Furthermore, the Big Mac and small fries is 6 grams lower in fat than the salad. If you choose the four-piece McNuggets and small fries, instead, it's only 430 calories and 26 grams of fat.

Burger King: Burger King only offers two salads: a side salad and a Chicken Caesar salad.