Nutrition
2.1 Classes of food
1) Food is the source of energy for all living things .
2) The importance of food :- a) Builds healthy bodies
b) Growth
c) Provides for carrying out work
d) Warms the body
e) Build new cell
f) Repair and replace damaged tissue
3) Food can be classified into seven main classes which are:-
* Carbohydrates, fat, protein, vitamins, mineral salts, roughage and water.
Carbohydrates
1) Carbohydrates are made up of carbon, hydrogen and oxygen.
2) There are three types of carbohydrates –sugar – starch – glucose
3) Food rich in carbohydrates include rice, potato, sugar , bread and banana.
4) Carbohydrates are our main source of energy.
Protein
1) Protein is made up of carbon, hydrogen, oxygen and nitrogen. Some protein also contains phosphorus and sulphur.
2) Food rich in protein include fish, mil, meat, egg white, and nuts.
3) Protein is require to build new cell for growth and replace damaged tissue.
Fat
1) Fat is made up of carbon, hydrogen, and oxygen but the ratios are different from that of carbohydrate
2) Food rich in fats includes palm oil, coconut oil, fish oil, butter and egg yolk.
3) Fat produce twice amount of energy compared with carbohydrates of the same weight
4) The function of fats include: - Supplying energy, insulator of heat, protecting internal organs.
Vitamins
1) Vitamins are required in small quantities only.
2) Vitamins can be classified in 2 group which is :- water soluble and fat soluble
3) Vitamins protect the body from various types of disease and maintain the health
of the body.
Mineral salts
1) Our body requires small quantities of mineral salts
2) Mineral salts help to maintain our body’s health.
