This is probably in Food Rules, a book I mentioned a couple days ago–it is hard to remember that many rules. But I happened to be aware of this long before I read that book.
Basically, the color of the food we eat determines the nutrients in the food. So, the greater variety of color in your diet, the greater variety of food, and thus, a more balanced diet with a variety of nutrients. Some people hate green vegetables. But they are important, so learn to like them.
Vegetables and fruits come in nine colors. Orange, yellow, red, purple, black, brown, white, green, and blue. For a list of what nutrients are found in what color of fruits or vegetables, go to http://www.deyale.com/index.php?option=com_content&view=article&id=22%3Ahow-many-colors-are-in-your-food&catid=1%3Ahealth-articles&Itemid=16
It is recommended that you eat at least one serving of each of these colors each day. That could be tough. Some of the foods simply aren’t in season all year round. But there are ways to modify your diet to include them.
For example, one year I planted purple carrots in my garden rather than orange ones. They tasted different, but they were SO yummy. Beans also come in purple. Potatoes can be white, yellow or even blue. When I haven’t included a red vegetable, I will cook with red onions. In fact, I usually do use red onions for that reason–more nutrients. Red cabbage versus green cabbage is another example. And what about the different colors of bell peppers? Is there a better orange vegetable than yams, which also come in a red color, called Garnet yams.
In addition to having different nutrients, the darker the color, the more nutrient dense a food. For example, iceberg lettuce has almost no nutritional value, except for fiber, which is also pretty low. It is mostly water. Romaine lettuce, however, is darker green and is loaded with Vitamin A. They are both lettuce, but each has a vastly different effect on the body.
When you plan your menus for the week, think about what they will look like. What will be most appetizing? Will chicken, potatoes and cauliflower look better? Or would you be better off substituting sweet potatoes and broccoli with a side salad? Which would appeal to the eye?
Have you noticed that some bold colored vegetables, like purple cabbage or red onions turn to a dull color if they are cooked too much? That is not only visually unappealing, it is a sign that many of the nutrients have been cooked out.
Finally, I have also saved the water remaining from steaming vegetables. I let it cool and put it on my plants. Some of the nutrients do get removed from boiling or steaming and they can be added to your plants. Just don’t use the cruciferous vegetables like cabbage or broccoli. Your plants will stink.
After you are done shopping in the produce section, your cart should be a gleaming basket of multi-colored jewels.