L earning O bjectives After completing this chapter the learner will be able to — define the terms — food, nutrition, nutrients, health, fitness and the role of food and nutrition in maintaining health. understand the term, balanced diet and apply the concept in planning and consuming diets. understand the basis for defining the Recommended Dietary Allowances (RDAs) and the difference between Dietary Requirement and RDA. understand the basis for classifications of foods into appropriate groups.
analyse the factors which influence adolescent food habits. identify the causes, symptoms and nutritional interventions related to eating disorders. Nutrition and health, in fact, are two sides of the same coin. They are, therefore, inseparable.
Health depends to a large extent on nutrition, and nutrition depends on the food intake. So food , is the most important single factor for health and fitness. Let us define and describe food, nutrition, health and fitness Food can be defined as anything solid or liquid which when swallowed, digested and assimilated in the body provides it with essential substances called nutrients and keeps it well. It is the basic necessity of life.
Food supplies energy, enables growth and repair of tissues and organs. It also protects the body from disease and regulates body functions. Nutrition is defined as the science of foods, nutrients and other substances they contain; and of their actions within the body including ingestion, digestion, absorption, metabolism and excretion. While this summarises the physiological dimensions, nutrition has social, psychological and economic dimensions too.
Nutrients are the constituents in food that must be supplied to the body in suitable amounts. These include carbohydrates, proteins, fats, minerals, vitamins, water and fibre. We need a wide range of nutrients to keep ourselves healthy. Most foods contain more than one nutrient such as milk has proteins, fats, etc.
Nutrients can be classified as macronutrients and micronutrients on the basis of the required quantity to be consumed by us everyday. The figure on the next page shows us the distinction between macronutrients and micronutrients.