As you know, I’m a big fan of whole soy foods because the phytochemicals (called isoflavones) they contain have been shown in hundreds of studies to help prevent heart disease and several forms of cancer. Like other soy foods, roasted soybeans – known as "soy nuts" – deliver these health benefits, and they’re a tasty and nutritious snack. A one-ounce serving (about one-quarter of a cup) amounts to 120 calories, 10 grams of protein and six grams of fiber. It also contains four grams of fat, three of them unsaturated. You can get roasted soy nuts flavored, salted and unsalted. Try tossing them into a salad for some crunch.
While they are a healthy snack, too many soy nuts can be fattening. A one-ounce, 120-calorie snack is reasonable, but two or three ounces daily will give you extra calories that soon will show up on the scale as added pounds. You also may want to watch your salt intake, especially with some of the flavored varieties. I prefer unsalted snacks myself.
The isoflavone content of a one-ounce serving of soy nuts may or may not be listed on the package label and can vary depending on the variety of soybeans used, the manufacturing process, and even the weather conditions where the beans were grown. But it can be as high as 83 mg per quarter cup, much more than the 40 mg I recommend that women get daily from soy foods such as edamame, tofu, tempeh and soy milk. (Asian women consume 20-80 mg of isoflavones daily and, as you may know, have one-fifth the rate of breast cancer that occurs among Western women.)
Andrew Weil, M.D.