Food, Nutrition, Health and Fitness consecutives


Food, Nutrition, Health and Fitness consecutives

Author: Aurora Luna Swanepeol

Category: Medical Science

Learning Objectives

After completing this chapter the learner will be able to understand -

• 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.


The onset of adolescence brings with it many profound many types of changes. The growth rate speeds up dramatically. This growth spurt occurs due to the activity of hormones that are effect on  every organ of the body and this makes healthy eating very important. The nutrient needs rise throughout childhood, peak in adolescence and then level off or even diminish as the teenager becomes an adult. The saying ‘‘You are what you eat” seems to be proven true. We eat different kinds of food such as dal, chapatti, bread, rice, vegetables, milk, lassi, etc. All these different kinds of food provide us with nutrients to keep us healthy and active. It is important to know what food to eat in order to stay healthy. The science of food and nutrients and their action on our health is called Nutrition.

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 on times.

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 every day.

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Figure: Vegan food

Balanced Diet

A balanced diet is one most important, which includes a variety of foods in adequate amounts and correct proportions to meet the day’s requirements of all essential nutrients such as proteins, carbohydrates, fats, vitamins, minerals, water, and fibre. This diet helps to promote and preserve good health and also provides a safety margin or reserve of nutrients to withstand short durations of deprivation when they are not supplied by the diet. The safety margin takes care of the days we fast, or the short-term deficiency of certain nutrients in the daily diet. If the balanced diet meets the Recommended Dietary Allowances (RDAs) for an individual, then the safety margin is already included since RDAs are formulated keeping extra allowances in mind.

Recommended Dietary Allowances = Requirements + Margin of safety

A balanced diet takes care of the following aspects.

1. Includes a variety of food items

2. Meets the RDA for all nutrients

3. Includes nutrients in correct proportions