Why Eating the Rainbow Is Good for You, According to Nutritionists

Some of our favorite foods are white, or whitish — bread, mashed potatoes, cauliflower, vanilla ice cream, to name a few — but if you limit yourself to pigment-free foods, you miss out on both the huge diversity of foods and also important nutrients. That’s because color (so long as it’s not artificial) is basically a shorthand for nutrients.

Dark orange or gold vegetables tend to be high in beta-carotene, explains Julie Garden-Robinson, a professor of health and nutrition science at North Dakota State University. Red fruits like watermelon and tomatoes contain high levels of lycopene, and orange foods like oranges and cantaloupe are good sources of vitamin C.

In general, the darker the color of the fruit or vegetable, the richer the concentration of phytonutrients, says Dana Hunnes, a professor of health science at the UCLA Fielding School of Public Heath. That’s why vibrantly colored leafy greens like kale and romaine have more nutrients — including vitamin B, iron, magnesium, calcium, and potassium — than iceberg lettuce, which has many of the same types of nutrients, only in much lower concentrations.

It follows, then, that eating foods of different colors equates to giving your body a diverse mixture of nutrients. And as a side benefit, Garden-Robinson adds that eating more fruits and vegetables may “crowd out less-healthful foods and promote a healthy body weight in the process.” In other words, if you eat more kale, you may be less inclined to eat that brownie. (We’re not so sure.)

To get the most out of a food’s nutritional content, look at the color of the part you eat. The anthocyanins, or antioxidants that may protect against free radicals, in a red apple, for example, are in the skin — not the flesh.

It’s a good idea, too, to add orange foods and leafy greens to your diet, as most people tend to fall short in those two categories, Garden-Robinson says. And you may also want to consider upping your intake of certain raw vegetables. Take broccoli, which is best eaten uncooked if you’re looking to maximize your intake of vitamin C. Boiling reduces the amount of vitamin C; frying basically obliterates it.

Still, despite claims from raw food advocates, heat doesn’t zap the nutritional value of all foods. In fact, heat increases the concentration of vitamin A in carrots, and the lycopene in tomatoes is fat-soluble. That means you get more of the nutrient when tomatoes are combined with a little oil, like in a sauce. Besides, notes Hunnes, even if you do lose a few nutrients here and there, it’s better to eat them cooked than to avoid eating them at all.

Really, the best advice is to have some of everything, Hunnes says: “There are certain nutrients that you can’t necessarily find in a leafy green vegetable. You do want to taste a little of all the colors.” So next time you’re at the farmers market or the grocery store, go ahead and try something new and brightly hued.

How do you eat the rainbow? Share with us in the comments!