All soy products are made from soybeans, mostly grown here in the United States. You can buy whole soybeans dried or canned, or in the produce section or freezer aisle as edamame, the common name for soybeans picked before theyre fully mature. (Edamame can be purchased either in pods or shelled.)
Soys biggest nutritional claim to fame is its complete protein, one of the only plant proteins that contains all nine essential amino acids our bodies need from our diets to function properly. This makes it an ideal substitute for meat, poultry, and eggs. In fact, a half cup of cooked soybeans supplies about one-third of your necessary daily protein, for a mere 149 calories (versus about 230 for one serving of cooked ground beef). That protein and the fiber it contains make it incredibly filling. Plus, soybeans are cholesterol-free and lower in heart-unhealthy saturated fat than meat and dairy.
Soy also packs a number of phytochemicals, including isoflavones, which may work together to help fight conditions like cardiovascular disease, osteoporosis, and breast cancer. (Though you might have heard that women with a history of breast cancer should avoid soy, recent research suggests thats probably not necessary, says Karen Collins, RD, nutrition adviser to the American Institute for Cancer Research.) To score soys benefits, get up to three servings a day, mostly from less processed forms like soybeans, soy milk, soy nuts, and tofu. "When soybeans are eaten close to their original state, you get more of their good-for-you attributes,"says Dawn Jackson Blatner, RD, author of The Flexitarian Diet.