This book is so advanced in it's approach to diet and nutrition that all other so-called diet books are now obsolete. I have been using Wolcott's book and system in my practice as a medical nutritionist and have found that it addresses every single problem I encounter. His determination of a person's "type" is simple and direct and the results are fantastic. This book is the only book a patient or healthcare provider will ever need to understand individual nutritional needs. It is easy to read and understand and is a must-have for anyone who is interested in optimum health.