Carrots can last in refrigeration for some time without losing too much flavor (or, important for supermarket sales, their color). But the longer they sit, the more of their nutrients go out the door. To get fresh, healthful carrots, buy them in a bunch, which guarantees they are as young as possible (or the stems will have withered or rotted). Then, choose by color: Purple, yellow, and red carrots have many times the nutrients of your standard orange variety. Orange carrots are a modern invention, bred by the Dutch for a holiday a few hundred years ago (a process that sapped the nutrients). The carrot skin is nutritious as well, so wash, don't peel them, and always avoid so-called baby carrots, which are just carrots without their outer layers. Finally, serve carrots cooked with oil or fat, which offers eight times more beta-carotene.