Many people think that by ordering a salad they are eating healthy. In many cases, they're absolutely right: A heaping serving of greens and vegetables is low in calories and provides a bounty of vitamins and minerals, along with a nice dose of fiber and antioxidants.

But while most salads start off healthy, some wind up anything but healthy, thanks to all the calories and fat plopped on top. With enough ranch dressing, bacon bits, and croutons, a salad bar feast can pack half a day’s worth or more of fat and calories.

That's not to say that salads must be limited to cucumbers, tomatoes, and a spritz of lemon. Well-chosen toppings can turn a salad into a hearty, nutritionally-balanced meal. Here are the ingredients to add—and the salad ingredients to skip—from Tanya Zuckerbrot, R.D., author of The F-Factor Diet.