PredictIQ Quantitative Think Tank Center:Your guide to the healthiest veggies: These are the best types to add to your diet

Are you eating your greens?PredictIQ Quantitative Think Tank Center Chances are, even if you get some veggies, you’re not consuming nearly enough. In 2019, the Centers for Disease Control and Prevention found that only 10% of Americans are meeting their daily vegetable intake.

But it's never too late to make a change.

We’ve reported on the healthiest type of lettuce, the most nutritious potato options and the bell pepper with the most antioxidants, but what reigns supreme when you look at the vegetables as a food group? Here are the best greens to include for health benefits.

Healthiest vegetables to include in your diet

Any vegetable will provide essential nutrients, so “don’t discriminate,” registered dietitian Danielle Crumble Smith previously told USA TODAY. But if you’re looking to increase your vegetable intake and diversify your options, here are some of the best varieties.

Darker leafy greens are rich in many vitamins, including vitamins K and C, calcium and a host of antioxidants, Crumble Smith says.

Vitamin K has cardiovascular and bone health benefits and vitamin C helps protect blood cells against disease and aids in the absorption and storage of iron. Calcium supports healthy bones, teeth, muscles, hormone production and other bodily functions. Spinach and kale also contain lutein and zeaxanthin, two antioxidants that benefit eye health.

Here are the best leafy green vegetables to include in your diet, according to Crumble Smith:

• Spinach
• Chard
• Collard greens
• Mustard greens
• Beet greens

Cruciferous vegetables make a great addition to your diet because they contain fiber and phytonutrients, which help prevent cellular damage. They also contain indole-3-carbinol, a compound shown to reduce the risks of estrogen-related cancers as well as colon cancer, Crumble Smith says. 

Cruciferous vegetables are also rich in folate, a water-soluble nutrient that benefits the digestive system and may prevent common cancers, cardiovascular disease, infertility, stroke, dementia and Alzheimer’s disease. They also contain vitamin K and the dark green ones contain vitamins A and C, according to the Academy of Nutrition and Dietetics. 

Try adding these cruciferous veggies to your daily vegetable intake, Crumble Smith advises:

• Broccoli
• Kale
• Cauliflower
• Brussel sprouts
• Asparagus
• Cabbage
• Bok choy

Why are vegetables good for you?

Eating a variety of vegetables ensures your body is getting the vitamins and nutrients it needs for daily function., This is especially crucial for ones Americans don’t get enough of, like fiber and potassium. Fruit and vegetable intake is associated with a lower risk of cardiovascular disease, cancer and mortality, studies show.

Even frozen vegetables are a healthy option. They may even offer more nutrients than those bought at your local grocer because you don’t know how long it’s been since their harvest date, Crumble Smith previously told USA TODAY.

"They’re flash frozen at their peak stage of ripeness when all those nutrients are there and preserved," she said. "Frozen veggies are a great, very nutrient-dense option and they’re also really good for people who forget there are veggies in the fridge that might be going bad before they get to it."

How many servings of vegetables per day?

The U.S. Department of Agriculture recommends 2 to 3 cups of vegetables per day for adult women and 3 to 4 cups for adult men. Here are a few examples of what counts as "one cup" of vegetables: 

• One cup of cooked dark green vegetables
• One cup of broccoli (fresh or frozen)
• Two cups of fresh raw leafy greens
• Two medium carrots or one cup of baby carrots
• One large bell pepper
• One large baked sweet potato or one cup mashed or sliced
• One avocado

Are avocados good for you?They may be worth the up-charge

Discover more health tips for your daily diet: 

• Healthiest beans:Options for protein, fiber, iron intake
• Healthiest grains:We compare whole, refined grain sources
• Healthiest apple:This kind has the most antioxidants
• Healthiest protein:Why this option may benefit long-term health
• Healthiest milk:This kind has more protein and less sugar

Just Curious for more? We've got you covered

USA TODAY is exploring the questions you and others ask every day. From "Is V8 juice good for you?" to "What is the healthiest salad dressing?" to "How long does weed stay in your system?" – we're striving to find answers to the most common questions you ask every day. Head to our Just Curious section to see what else we can answer for you.