Never heard of maca? It’s A Peruvian root vegetable that's a staple in South American cooking. Here's why you should get acquainted: It's considered an aphrodisiac, stamina enhancer, and anxiety reducer. "While more scientific evidence is needed to substantiate these claims, the vitamin and mineral content is reason enough to keep this stocked in the fridge," says Silber. "A little maca powder added to smoothies or oatmeal will provide rich amounts of iron and B vitamins, all of which can enhance energy and mood." Find it in natural food or nutritional supplement stores.