Salads, at their simplest, are a mix of some really good things. Lettuce or spinach. Carrots. Tomatoes. Cucumber. Veggies of all sorts gather here to offer you their goodness. But if you’re keeping them naked, you might be missing the best of what they have to offer.

“Salad dressing is wonderful,” says Karen From, nutrition and health education specialist with the University of Missouri Extension Office. “And it tastes really good.”

For several years, studies at various universities have stressed the importance of including fat along with your veggies. According to the Linus Pauling Institute at Oregon State University, cartenoids are absorbed when fat is present.

Cartenoids come from fruits and vegetables and are responsible for the yellow, red and orange colors in those fruits and vegetables. So why do we need them? According to the Linus Pauling Institute, Vitamin A “is essential for normal growth and development, immune system function, and vision.”

That good fat also helps your body reap the benefit of your foods’ antioxidants, Ms. From says.

That doesn’t mean you should pour on the ranch, however.

According to Robert Etherton, store manager at GNC, ranch dressing is one of the first things they get people off of when trying to lose weight.

Ranch also does nothing for the veggies in your salad. The dressings you need, it turns out, are those with monounsaturated fats. Remember these? They help lower the bad cholesterol and raise the good cholesterol.

“We encourage the good fats,” says Sheri Caldwell, store nutritionist at Hy-Vee.

Foods that have monounsaturated fats also help lower the risk of heart disease and strokes, according to about.com.

And it’s that fat found in salad dressings that have oil bases that help the body absorb these nutrients. According to Ms. From, the dressings you want are olive oil or canola oil based. And, Ms. Caldwell says, extra virgin olive oil’s even better because it’s been through less processing.

But here’s another caution — just because you can use your oil-based dressings, you still need to limit them because they are high in fat.

Ms. From recommends a tried-and-true dieter’s trick — dipping your fork or salad tongs in dressing with each bite. That way you get enough for taste but your food’s not swimming in it.

So what if you choose a low-calorie dressing? Does that mean you could have more?

Not really.

In 2004, the Journal of Clinical Nutrition reported that, according to a study, eating salads with full-fat dressing resulted in better nutrient absorption than low-fat dressings.

If you’re not big on dressings, though, don’t despair. Add other kinds of healthy fat, such as a little olive oil, avocado, sunflower seeds or almonds, and your body will still get all the good stuff.

And be smart about what else is on your salad, Ms. From says.

Ms. Caldwell recommends building your salad around veggies and fruits, not bacon bits or high-fat dressings. Don’t be afraid to add fruit.

And, Ms. From says, “always stay away from croutons.”