Dietary assessment is a multifactorial process aimed at recording and evaluating the health, growth, or nutritional status of individuals or populations. 

Its main components include medical and socioeconomic history, medication history, dietary intake assessment, as well as the evaluation of anthropometric, biochemical, and clinical indicators. Each of these parameters requires both the measurement and collection of data and the evaluation and interpretation of these in order to complete the overall picture of the individual's or population's health status.

In this book, the presentation of the subject of dietary assessment is organized into four major thematic sections, the first of which includes elements of the patient's history, the second for the assessment of nutritional status and body composition, the third for clinical examination, and the fourth for biochemical markers used in patient assessment. All these sections are presented in twelve chapters, grouped into four sections. 

The first section presents the various types of histories (Chapter 1) with a particularly extensive reference to the most important methods of taking dietary history and the ways of evaluating the data derived from them (Chapter 2). At the end of the first section, the components of energy expenditure and the ways of measuring or calculating it are presented (Chapter 3). 

The second section deals with basic principles and ways of assessing body composition (Chapters 4 and 5). The importance of clinical examination in the process of dietary assessment is emphasized in Chapter 6, which constitutes the third section. 

Finally, in the fourth section (from Chapter 7 to Chapter 12), there is a detailed presentation of the biochemical markers used both in the diagnosis of chronic diseases and in the process of assessing dietary intake of nutrients.

In an effort to make the reader aware of current data in the field of dietary assessment, special emphasis has been placed on presenting examples and contemporary research results. Having received the appropriate stimuli, one can then delve into the international literature as well as the research field of dietary assessment of individuals or populations. 

The involvement of the health scientist in the field of dietary assessment, having as a starting point and guide this book, may perhaps be the best proof of fulfilling its purpose.
Finally, I would like to warmly thank all the authors and collaborators who contributed to the completion of this book.