I found this on Food, Inc. and you might be in shock to see some of your favorite salads, from your favorite restaurants are on this page. Just because it is a salad, and lettuce is involved, does NOT mean it is always a healthy choice. Sometimes you are better off choosing something you would rather have (unless its fried) and modifying it. If you are eating salads like a wedge with ranch and bacon, or any salad with iceberg lettuce, it does not have the nutrients like darker lettuce has.
Take the time to look at this link:
Restaurants Worst Salads!