This hot tip arrives just in time for winter stews: From the lowly white button to the exotic cremini and shitake, mushrooms are loaded with B vitamins (including niacin and riboflavin), selenium, healthful enzymes—even some antiviral compounds. One medium-sized portobello carries more potassium than a banana or a glass of OJ.

For low-cost, low-calorie nutrition, replace meat with 'shrooms. Once you've tasted a quesadilla or spaghetti sauce with portobellos or other flavorful fungi (sauté them first with garlic in olive oil or butter), you'll never crave hamburger again. Well, almost never.