Amazon.com Amazon.com Review (ISBN 0060393106, Hardcover)

The world has grown increasingly curious about the benefits of soy in recent years. Not only is it a dietary staple of the people of Okinawa, who live longer than anyone else, it also seems to help prevent heart disease and breast and prostate cancer.

So author Barry Sears has now modified his popular Zone diet to include soy and made the whole thing just as easy to follow as before. Fill a third of your dinner plate with a dish high in soy protein and the other two-thirds with fruits and vegetables, and you've got the Zone dialed in.

Not surprisingly, Sears is just as down on starchy foods--potatoes, pasta, rice, breads, and cereals--in The Soy Zone as he has been in his past books. He says they trigger too large an insulin surge, which leaves people feeling sluggish a couple of hours after the meal, and sends them chasing after another burst of quick energy in the form of other insulin-generating carbohydrates. That, he says, makes people fat. He also comes down on traditional vegetarian diets for that same reason: "The insidious long-term consequence of a grain-based vegetarian diet is the constant elevation of insulin levels," he writes.

The payoffs of taking this detour into the soy zone are immediate, Sears notes. He promises that people following his diet will think better, feel more energized, look better (he predicts a five-pound weight loss after two weeks on the Zone diet, including about two to three pounds of retained water), and experience fewer sugar cravings. Even better, the addition of 50 daily grams of soy to the diet should reduce total cholesterol levels by about 9 percent, shrinking the risk of heart disease by 20 percent. Add it all up and you get a longer life at a lighter weight--a heck of a promise, but one Sears, as always, is confident the Zone can deliver. --Lou Schuler