The purpose of this book is to present the principles of food chemistry and nutrition with as many of the scientific facts as space permits, and as are deemed most important an effective grasp of the subject. Designed primarily to meet the needs of college classes, it is hoped that the book many also continue to be of service to other readers who are interested in the kinds and amounts of substances needed in our nutrition, the considerations which should underlie our judgments of food values, and the choice and use of foods for the nutrition improvement of life.

Nutrition has been found to play an important part in the maintenance of the bodies reputed "Steady States" (Its relatively constant internal environment).Yet also it is now found this internal environment is not so rigidly fixed as had been supposed, and is influenced for better or worse by what we take into the body as food, even within the range of conditions universally accepted as normal.