1. I. NTRODUUTION
1.1. Definition Human Nutrition
A deﬁnition of a nutrient is any chemical substance that can be used by an organism to sustain its metabolic activities. These metabolic activities in humans and other animals include the provision of energy, growth, renewal of tissues, reproduction and lactation. Human nutrition is a process by which substances in food are transformed into body tissues and provide energy for the full range of physical and mental activities that make up human life (Burnett, 1989).
The study of human nutrition is interdisciplinary in character, involving not only physiology, biochemistry, and molecular biology but also fields such as psychology and anthropology, which explore the influence of attitudes, beliefs, preferences, and cultural traditions on food choices. Human nutrition further touches on economics and political science as the world community recognizes and responds to the suffering and death caused by malnutrition. The ultimate goal of nutritional science is to promote optimal health and reduce the risk of chronic diseases such as cardiovascular disease and cancer as well as to prevent classic nutritional deficiency diseases such as kwashiorkor and pellagra (Fieldhouse, 1986).