Setting the Stage: The Need of Water and Food

This chapter sets the stage and provides current knowledge related to water and food necessities. Both water and food are essential for life and major keys to survival. Although water is not included in the diet formulation, it is considered an inorganic nutrient, and it is consumed mostly as drinking water and from feedstuffs. A further source of water is metabolic water or oxidation water, which is produced when macronutrients (carbohydrates, fats, and proteins) are oxidized to yield energy. Water comprises 75% body weight in infants to 55% in the elderly and is essential for cellular homeostasis. Similarly, the macronutrients provide energy (measured in Kcals) and essential components to sustain cellular homeostasis and life. These macronutrients are consumed in different combinations and ratios to help achieve different goals and health (disease) states. In this chapter, a brief description of these nutrients is provided.