Why do some diets produce life-changing results for some people but not for others? World-renowned health and fitness coach Dr. Joe Christiano updates his tested and proven weight-loss program based on the simple concept that your blood type-O, A, B, or AB-determines your body's ability to absorb nutrients, fight off disease, and lose weight. Revised to include protocols for detoxification and address healthy colon function, this updated edition explains how a well-balanced eating plan based on blood type is pivotal for losing weight and keeping it off for life.