The title and subtitle are misleading. Although the so-called "China Study" forms the basis for the conclusions in this book, the book goes well beyond that one study. This is also not a diet book. This book is about the connection between food and disease, more specifically about how animal protein affects our health negatively. The subtitle does not overstate the case when it refers to the book's research as having "startling implications".
Campbell has been on the forefront of thought and research about nutrition since the start of his career. His origin in a farm family, where he learned that meat and more meat is good for everyone and where drinking milk was a way of life, makes his position in this book all the more remarkable. In spite of his long-held beliefs in the health value of animal protein he kept his eyes and mind open and discovered and conducted study after study that linked animal-food diets with cancer, heart disease, and a large number of other diseases. When he naively brought his discoveries to the institutions where he worked, hoping for the go-ahead to do more and to get the word out, he was quietly shoved aside.
This book, therefore, goes beyond telling us the results, telling us to eat a plant-based diet to avoid or help stabilize heart disease, diabetes, cancer, auto-immune diseases, and more. In it we learn of many of the specific studies that convinced him that eating primarily animal proteins is bad for your health. Not just bad for heart or diabetes patients, but bad for everyone. He explains the effects of genes, how some diseases (auto-immune) cause the body to attack itself, and even describes the specific mechanism that causes our bodies to use animal proteins in a way that can harm us.
Campbell also explains the political and medical climate. We've heard it before and here it is again: Industry controls government institutions as well as educational and medical institutions. Industry has the money and uses it wisely to change results and recommendations, to water down any suggestion that the standard American diet is not what it should be.
It isn't a weight-loss book, but if you follow it and you have a weight problem your problem could be solved. As I am fat myself I know there are other forces that make it very difficult for us, cravings that are far stronger than unfat people have ever felt. There is no doubt, in any case, that following this "diet" - which is a simple list of what to eat and what not, without any portion sizes (just "eat as much as you want" and "eat less" recommendations) - will make anyone healthier.
The claims made in this book are radical. Make no mistake. If followed, the American diet would make a huge swing and animal agriculture would be on its way out. Yet it isn't nearly as difficult to follow these recommendations as many think. One of the primary reasons doctors don't like to ask their patients to make radical changes is that they believe their patients will give up, that it will be too hard. But based on my own experience as well as some cited in the book, going in the plant direction opens up whole worlds that meat-eaters rarely explore. Instead of reducing our choices, this change increases them. It is also a way to never be hungry again. Diets that make people hungry may seem good for the soul but they aren't good for the body.
For proof of these claims that is as definitive as it is possible to get, read the book. It will probably change your life and it may save it.