Answers to Essay Questions on Nutrition

Food and Nutrition
Essay Questions
1. Water is an essential constituent (part of a whole) of living protoplasm (living part of a cell). About 70% of the body weight of a mammal is water.
• For transport- it is the main constituent of blood and body fluids and acts as a medium for the transport. Nutrients, waste substances, hormones etc are transported in solution.
• For chemical reactions to take place- a solvent for food substances during digestion (breaking down of complex food molecules to simple molecules); a solvent which act as a transport of materials in solution. Example: Transport digested food substances from the intestine to other parts of the body; excretory products from the tissue cells to the excretory organs for removal.
• For temperature regulation - Water helps to regulate the body temperature; excess body heat is removed by the evaporation of sweat from the skin surface. The cooling effect is vital in preventing overheating of the body.
• For lubrication- main constituents of the synovial fluid in synovial joints and mucus in alimentary canal.

2. Regular (daily), hard physical work – Example: Construction workers, workers who work under the sun for long hours.
- Doing hard physical work means that he should have a diet which provide sufficient energy to maintain his high basal metabolic rate and to sustain his strenuous manual activity at work.
- He should have a balanced diet, which consists of 7 constituents of food, in particular a high proportion of carbohydrates, proteins and water.
- Carbohydrates is the main source of energy, e.g glucose is the main respiratory substrate, which is oxidized to produce immediate energy.
- Proteins for growth of new tissues and replacement of cell components and the formation of strong muscles, tendons and ligaments.
- Drinking more water replaces the water loss in sweat produced during the hard, physical activities and help to maintain a constant blood concentration.

3. Starvation occurs when there is a complete lack of all types of food for consumption or nutrition for the body over a long period of time due to food shortage.
Starvation results in a huge loss of body weight as storage of fats and proteins in muscles are broken down to provide energy for the vital functions of the body to continue.

Malnutrition is when a person whose diet lacks one or more essential constituents of a balanced diet, either having too much of certain kind of food or having too little of a certain kind of food.

4. Famine is when a country do not provide enough food for its population. Problems contribute to famine are that the large areas of the world especially developing countries do not produce enough food for its increasing population (overpopulation).
 Poverty- when the country is too poor, even the cost of transporting food is too high for them. But in developing country, some do not have to pay for the transport. They could have grown their own crops. But without the education and knowledge to grow crops, food availability will provoke famines.
 Failure of crops in massive scale due to drought, flood, earthquake and other natural disasters or due to diseases.
 War or political instability- affects the distribution of food in that region where some parts may not receive any food at all for a long period.
 Poor farming techniques- education on improved farming techniques.
 Crop failures due to diseases- improve methods on developing disease resistant crops and disease control.

5. Examples of plants are vegetables such as spinach, broccoli, fruits.
Most vegetables and fruits especially high fibre vegetables such as broccoli and spinach contain indigestible cellulose cell wall which act as a fibre. The cellulose fibre, added to the bulk of food in the alimentary canal to assist peristaltic movement in the large intestine. This helps to prevent constipation hence reduce the risk of colon cancer.

6. Both carbohydrates and fats contain the three main elements which are carbon, hydrogen and oxygen.
Carbohydrates contain hydrogen and oxygen atoms in the ratio of 2:1. Example: C6H12O6
Fats on the other hand contains much less oxygen than hydrogen. Example:
C57H110O6
The elements in fats do not have a general formula like carbohydrates.

8a. Components of a balanced diet contains the right amount of carbohydrates, fats, proteins, vitamin, minerals, water and dietary fibre.
8b. Carbohydrates – Examples: bread, noodle, cakes, rice.
Importance of these carbohydrates in the functioning of the human body are:
It is the main and immediate source of energy.
To synthesise lubricants, e.g mucus which consists of a carbohydrate and a protein. The mucus lining the respiratory system in man traps dust particles.
Proteins- examples: meat, peas, beans.
It is a source of energy. It is for growth and repair of worn out cells and damaged tissues. For the synthesis of enzymes and hormones and antibodies. It is also for building up the body structures such as hair, nail, red blood cells, muscles, ligaments and tendons.
Fats- act as a source of energy. It provides insulation.

9. Meat- consists of proteins, proteins act as a source of energy.
 It is for growth and repair of worn out cells and damaged tissues.
 For the synthesis of enzymes and hormones and antibodies.
 It is also for building up the body structures such as hair, nail, red blood cells, muscles, ligaments and tendons.
Beans consists of proteins and potatoes consists of carbohydrates.
 Proteins act as a source of energy.
 It is for growth and repair of worn out cells and damaged tissues.
 For the synthesis of enzymes and hormones and antibodies.
 It is also for building up the body structures such as hair, nail, red blood cells, muscles, ligaments and tendons.
• And carboydrates is the main and immediate source of energy.
• To synthesise lubricants, e.g mucus which consists of a carbohydrate and a protein.
• The mucus lining the respiratory system in man traps dust particles.

Fresh fruits contain fibre and vitamin C.
• Fibre aids in peristalsis in the large intestine and prevents constipation.
• Vitamin C helps to provide healthy gums and quick healing of wound and maintaining healthy epithelial tissues.

10. A balanced diet is a diet which contains the right amount of carbohydrates, fats, proteins, vitamins, minerals, water and dietary fibre to meet the daily requirements of the body.

12. Constipation is caused by having too little food which consists of fibre in the diet and having too much of the other nutrients such as carbohydrates, proteins and fats in the diet.

(ii) Obesity means having too much certain types of food in the diet. It is caused by eating too much high energy food in the diet.

13. Rickets is caused by not having enough calcium in children or lacking of vitamin D in the diet.

Symptoms are: Weak bones, bones fractured easily, bow legs.