ICSE Class 6 Biology Chapter 7 Health and Hygiene

Health and Hygiene

When Are You Considered to Be in Good Health?

Health is not just the absence of disease but a state of complete physical, mental and social well being. The World Health Organization (WHO) has defined health as "Health is a state of complete physical, mental and social well being and not merely an absence of disease or infirmity." Have you ever wondered why some children fall ill rarely whereas others fall sick quite frequently?

Factors affecting the maintenance of good health are as follows:

- Balanced diet

- Personal hygiene

- Community hygiene

- Adequate exercise and rest

- Protection from the communicable diseases

Food and Health

All living organisms need food. Food contains nutrients, the substances which the body needs to grow and remain healthy. The nutrients act as a fuel and the energy derived from them helps the body to perform various activities like running, jumping, walking, swimming and many more. Nutrients keep us free from diseases and are also responsible for the growth and repair of our body.

There are five types of nutrients in our food - carbohydrates, fats, proteins, vitamins and minerals. In addition, water is a medium, that is, essential for all the metabolic activities in our body. Though different food items may contain more than one type of nutrient, each food item is generally rich in one of the nutrients. Nutrients have specific functions. Food can be divided into three groups depending on their action on the body.

- Energy-giving food

- Body-building food

- Protective food

Let us now discuss about various nutrients.

Teacher's Note

Understanding nutrients helps students make better food choices at lunch and snack time, recognizing that energy and strength for sports come from balanced eating.

Carbohydrates

Carbohydrates are the main source of energy. Wheat, rice, bread, noodles, potatoes and fruits are rich in carbohydrates.

Fats

Fats give about twice as much energy as carbohydrates. Fats protect us from cold. Fats are found in oil, ghee, butter and nuts. Carbohydrates and fats together are also known as energy-giving foods.

Proteins

Proteins help in the growth of our body and repair worn-out tissues. Pulses, beans, meat, fish and nuts are the main sources of proteins. Since proteins help in the growth of the body they are also known as body-building foods.

Vitamins

Vitamins are needed in small quantities but they are required to remain healthy and proper growth. Some of the vitamins are named as vitamins A, B, C, D and so on. A single food item does not contain all the vitamins though milk has most of them except vitamin C. Vitamin C is present in orange, lemon and other fruits. Vitamins are also found in cereals, pulses, vegetables, fish, meat and eggs.

Teacher's Note

When students learn that different foods provide different vitamins, they understand why eating a variety of colorful fruits and vegetables every day keeps them energetic and disease-free.

Minerals

The nutrients that help the body to function normally and to use other nutrients properly are known as minerals. Minerals generally do not give any energy. Minerals like calcium and phosphorus are needed for proper growth of bones and teeth. Iron is needed for the manufacturing of red blood cells. Some of the sources of minerals are milk, green leafy vegetables, meat and pulses.

Since vitamins and minerals protect the body from many diseases, they are known as protective foods.

Water

Water is very important for our body because all the chemical changes that take place in the body occur with water as the medium. It is needed for digestion of food and removal of waste products. It is also essential for maintaining body temperature.

Roughage

Besides the nutrients mentioned above and water, our diet should also contain roughage or fibre. It can not be digested but it adds bulk to the food that prevents constipation. Fresh fruits and raw vegetables are rich sources of roughage.

Balanced Diet

Growing children and teenagers need more proteins and carbohydrates as compared to old people. Proteins help in the growth of their body and carbohydrates give them energy for playing and other activities. Pregnant women and feeding mothers need more nutrients in their diet. Females need less carbohydrates and fats than males because of their build-up. A person doing physical work needs more energy and therefore more carbohydrates than a person doing a desk job.

One should eat a balanced diet. A balanced diet gives us all the required nutrients, that is, carbohydrates, fats, proteins, vitamins, minerals and roughage in the right proportion. A balanced diet depends on a person's age, gender and the type of physical activity he or she does.

Teacher's Note

When students understand that different people need different amounts of food based on their age and activity level, they realize why their growing bodies need more food than their grandparents' bodies do.

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