The more colorful a fruit is, the better it is for you

Most of us don't get enough fruits and vegetables. What a shame, considering that just five servings of fruits and vegetables daily can reduce the incidence of cancer by 20 percent.

Eating more fruit and vegetables can also deliver improved exercise performance, a stronger heart, better memory and reduced diabetes risk. To achieve the maximum benefit, think of the rainbow when strolling through the produce aisle. Colorado State University researchers reported that subjects obtained more health benefits if they consumed a greater variety of colorful produce: a result attributed to the greater amount and variety of disease-fighting phytochemicals darker hued fruits and vegetables contain.

Blueberries: Blueberries contain a lot of anthocyanins, a group of antioxidants. A recent study found blueberries to have the highest antioxidant activity of all fruits. Other studies show a daily dose of blueberries can improve memory and suppress tumor growth. Blueberries' high antioxidant content may also hasten post-workout muscle recovery -- something that takes longer and longer as we age. A bonus is you get this big nutrition bang for just 85 calories per cup, so add a handful to your cereal, yogurt or protein shake.

Dark Green and Leafy: Salads and sautéed greens should be staples of your diet, but iceberg lettuce is a big nutritional dud. Instead, opt for its darker relatives such as spinach, kale, Swiss chard and collard greens. These greens contain performance-enhancing nutrients such as beta-carotene, vitamin K, vitamin C, iron, magnesium, folate and potassium. A recent study in Neurology reports that two servings of green leafy veggies per day slowed cognitive decline by 40 percent. Kale and other greens are an outstanding source of lutein, an antioxidant that fights cataracts and macular degeneration.

Sweet Potatoes: Sweet potatoes have a very different and more beneficial nutrition profile than regular potatoes. Exceptionally rich in beta-carotene, sweet potatoes can boost immune system, eye and lung health. They are also full of complex carbohydrates that your muscles require to exercise at high intensity, so consider adding sweet potatoes to soups or serving it baked alongside fish, chicken or steak.

Kiwi: Believe it or not, one kiwi fruit has more vitamin C than the much larger orange. Plus, you get almost 3 grams of appetite-squashing fiber to boot. Other significant nutrients of the kiwi that'll keep you going strong on the playing field include potassium, magnesium, vitamin E, copper, phosphorus, riboflavin and beta-carotene -- all for less than 50 calories. Norwegian researchers found that daily kiwi consumption helps lower the risk of cardiovascular disease (by reducing the stickiness of the blood, as well as reducing triglyceride levels). Because it is full of natural sugars and easy to digest, the kiwi is a smart pre-workout snack idea.

Here are a few more not-to-be-overlooked produce picks.

Tomato (Lycopene)
Broccoli (Folate)
Mango (Beta-carotene)
Brussels Sprouts (Vitamin K)
Strawberries (Vitamin C)
Red bell pepper Lycopene)
Avocado (Heart healthy fat)
Cantaloupe (Beta-carotene)
Asparagus (Folate)

Matthew Kadey is a Toronto-based dietitian and freelance writer (mattkadey.com).