Their healthy protein content makes them a good option even if you're not one of the growing number of people going "flexitarian," or opting to eat less meat.
Here's your guide to making this legume a regular and great-tasting part of your diet.
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 they're fully mature. (Edamame can be purchased either in pods or shelled.)
Beyond whole beans, soy takes on a number of different guises. Roasted soybeans are sold as soy nuts or ground into soy nut butter. Soybeans can be soaked in water, cooked, and filtered to make soy milk and soy yogurt. Adding a coagulant to soy milk curdles it, producing tofu, which ranges in texture from "silken" (very soft) to "extra firm," depending on how much liquid is removed.
Soybeans can also be fermented into a paste called miso (the base for miso soup) or a cake or patty called tempeh, which is often used in place of meat in sandwiches or grilled and eaten on its own. Finally, soy can be found in many packaged foods -- such as frozen meatless burgers, cereals, and energy bars -- often in the form of "soy protein isolate," meaning it's mostly the protein from soybeans you're getting.
The power of soy
Soy's 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 that's probably not necessary, says Karen Collins, R.D., nutrition adviser to the American Institute for Cancer Research.)
To score soy's 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, R.D., author of The Flexitarian Diet.
You may get slightly more nutrients from fermented soy foods like miso and tempeh, since the fermentation process can make those nutrients more absorbable by the body, says Blatner, but all forms of the legume deserve a place on your plate.
Two exceptions: First, avoid soy isoflavone supplement pills and powders. Research hasn't yet determined how much of it's safe to take, says Collins. Plus, unlike whole soy foods, they don't give you the full range of phytochemicals and other nutrients, such as B vitamins, which help with bodily processes like metabolism and keep your DNA healthy.
And though foods made with soy protein isolate (like soy burgers and soy dogs) do usually pack less saturated fat than their meat counterparts, they also tend to be loaded with sodium and additives, so don't make them a staple.
Easy ways to eat soy
Look for simple places to swap soy in for other foods and drinks. Snack on soy nuts instead of cheese; use soy nut butter instead of peanut butter for a change of pace (you may not be able to tell the difference!). Soy milk is a great alternative for the lactose intolerant (just avoid sweetened ones, which pack extra sugars).
Soybeans and tofu take a bit more prep, but not much. Here's how to make them taste great, fast:
• Steam or boil edamame for 3 to 5 minutes. You can purée them into hummus instead of chickpeas, or just sprinkle the pods with sea salt, chili powder, Chinese five-spice powder, or any other spice you like, and squeeze the beans into your mouth.
• Because it's so soft, "silken" tofu works well as a thickener for sauces, dips, and smoothies. The denser texture of "firm" or "extra firm" tofu works best for stir-frying, grilling, or baking. Just remove extra moisture first so it's not mushy: Lay a clean kitchen towel on a cutting board and place tofu on top. Cover with another clean towel and cutting board, then place a heavy pot on top. Allow it to rest for about 1 hour. Cut into cubes or strips and cook. Tofu will soak up the flavor of any dish it's in; you can also marinate it as you would meat and poultry.
• Prepare whole soybeans the same way you would other beans: Cooked into soups or chili, added to Mexican dishes, or tossed cold in salads, they bring new flavor to your favorite dishes.