If you’re making a low-fat salad, might as well top it with a fat-free dressing, right? Wrong. Despite the common perception that fat-free dressing helps your body, it actually deprives you of fats necessary to absorb the important nutrients in vegetables. Iowa State University researchers found that regularly drizzling the fat-free stuff over a veggie-rich salad compromises the body’s ability to take in carotenoids—antioxidants in vegetables that boost your immune system. Basically, the good guys need some dietary fat to fight off the bad guys! Help your body out—and avoid coming down with something this winter—by reaching for an olive, canola, or other nut oil-based dressing. (It'll make for a more satisfying meal, too.) Check out Annie’s Naturals for some great options, or try making your own.