It is common knowledge that food is essential for health. Everyone eats food and most people
":we an opinion on which foods are better for you. So why do we need nutritionists? What's more,
why does advice on nutrition always seem to change? The chapters in this book will address these
questions from several perspectives.
One short answer to the quandary is that nutrition is both a science and a practice. The World
Health Organization (WHO) defines nutrition as 'the intake of food, considered in relation to the
body's dietary needs' . As a science it builds a very broad knowledge base from a range of disciplines
that practitioners are then able to apply. A great deal of nutrition knowledge comes from the basic
sciences such as chemistry, biochemistry, biology and physiology. Other knowledge comes from
health disciplines such as epidemiology, dietetics and medicine, and then from the humanities such
as sociology, anthropology and the study of economics.
The unifying factor is the need to better understand the relationship
between food and health. Because this is a complex relationship, it needs
to be considered from a number of different angles, but they can aU come
together to represent the science of nutrition.