For most Americans it requires a bit of a seachange in eating habits, but it's well worth it. With the right foods, you can lose weight while eating as much as you want(I work in a very physically demanding job, build up a whale of an appetite, and teeny portions of food are simply NOT going to cut it!).
His tone can be a bit magisterial at times and I personally don't share his dislike for soybean products, but the science and reasoning behind this book are undeniable. If you are serious about losing extra weight and living healthier, get this book. Read it, absorb it, make the change, and live better.