1. 1. 4 Nutritional deficiency and excess which form the metabolic enzyme structure of the individual. It is not possible to live for more than 2-3 minutes without oxygen. However, life can continue with 1. 1. 5 Social, population and environmental out water for between 2 and 7 days depending influences on nutrition upon the ambient temperature and the amount of exercise being taken. Survival without any food at The reliable provision of food requires an orga all, but with water, may be for 60-120 days, nized society. A society that is disorganized depending upon the body stores. Females and through war, epidemics of infections or natural those with considerable subcutaneous fat survive disaster is less able to produce or deliver food for longer than slightly built males. than a well-structured stable society with a suffi There are individual responses to nutritional ciency of healthy workers. It is important that deficiency and excess. Though in general weight food is grown which is appropriate for the partic increase in association with overall excessive eat ular population's social, cultural and religious ing and weight loss is associated with inadequate beliefs. The influences on nutrition (Figure 1. 1) dietary intake. The failure to provide the essential include: amino acids, fats, vitamins and trace elements leads to specific lesions which may progress to • food availability and intake morbidity and death.

The Principles of Nutrition for Practitioners and Students discusses the principles of nutrition—a subject which becomes more and more terrifying to the learner with each addition to the complex of vitamins. The system of question and answer which has been adopted in the book will appeal to all students. The whole subject of vitamins is both efficiently and attractively presented, and gives not only a clear outline of the principles of nutrition but will certainly stimulate enthusiasm for this study which has, so often in the past, produced, if not terror, at least apprehension in the hearts of many. The book is organized into seven parts. Part I discusses the importance of food to health. Part II deals with the health impacts of vitamins A, D, B, C, and mineral salts. Part III focuses on the role of protein in the growth and repair of the body while Part IV covers the body's heat and energy production. Part V presents studies on the nutrition of individuals and groups. Part VI takes up issues of feeding such as rationing; the enrichment, drying, and preservation of foods; staple foods, and milk. Part VII considers world health issues, including the unequal distribution of food and variations in food consumption.

The book presents a detailed and authoritative exposition of the basic principles and applications of biochemistry. It thouroughly covers the syllabus recommended by MCI for undergraduate medical students. It focuses primarily on the fundamental concepts and explain them in detail. Numerous line diagrams, in an attractive two-colour format, are provided to illustrate the concepts and help the students in grasping their significance. Medical applications of biochemistry are discussed through extended examples and clinical cases. About the Author : - Dinesh Puri, Professor, Dept. of Biochemistry, University College of Medical Sciences and Guru Teg Bahadur Hospital, Delhi.