Deficiency of proteins in the diet for a long time results in swelling of face and neck, undergrowth of the body, etc. This is because proteins are the building blocks of the body and should be taken in sufficient amounts. 

Goitre is a disease in which the thyroid gland in the body does not work properly. This happens due to low intake of iodine in diet. 

Anaemia refers to low haemoglobin/blood level in the body which occurs when we do not take enough iron in our diet. This is because iron forms haemoglobin, which is a major component of our blood. 

Fruits and vegetables are a major source of vitamins and minerals. Washing and peeling more than required result in the loss of these two nutrients from them. 

Vitamin C is a nutrient, which can not tolerate high temperature and gets destroyed on over heating. 

Proteins, carbohydrates, fats, vitamins, minerals, water and dietary fibres are the substances which help in the optimal functioning of our body and form the various components of our balanced diet. 

Calcium, iodine and iron are minerals required by the body; whereas vitamin D is a vitamin and is the odd one out. 

Deficiency of proteins in the diet for a long time results in swelling of face, swollen neck, under growth of the body and diarrhea etc. This is because proteins are the building blocks of the body and should be taken in sufficient amount. 

Potato and rice are rich sources of carbohydrates. Both are abundant in starch. 

Scurvy results due to lack of vitamin C and is basically symptomized when our gums start bleeding. 

The lack or excess of anything is harmful, e.g. lack of fat lowers the body energy and intake of excess fat results in obesity.

Deficiency of vitamin D - Rickets

Deficiency of vitamin C - Scurvy

Deficiency of vitamin B - Beri-beri

Excess loss of water -- Dehydration

Deficiency of vitamin D - Rickets

Deficiency of vitamin C - Scurvy

Deficiency of vitamin B - Beri-Beri

So, scurvy is the disease which is prevented by the intake of citrus fruits. 

Vitamin A is the one which helps in keeping our skin and eyes healthy. Carbohydrates and fats are the energy providing foods and proteins are the basic building blocks of the body. Vitamin D also helps in maintaining the calcium requirements of the body. So, the deficiency of vitamin D and calcium in the body causes bones and tooth decay. 

A person who does not take proteins and carbohydrates in his diet for long, he may become so lean and thin that he will not be able to walk properly and his growth may also stop completely. This is because these two are the major nutrients for our body. 

Sufficient amount of iodine is required by our body for maintaining a balanced mental status. 

Vitamin D maintains the proper functioning of bones and teeth. It also helps our body to use calcium and thus prevents rickets. 

Goiter - swollen neck glands

Scurvy - bleeding germs

Rickets - bow shaped legs

Beriberi - weak muscles and laziness 

Vitamin C helps body in fighting against infection and also in healing wounds. 

Lack of any nutrient in the body causes one or the other diseases in the body.

For example, Deficiency of vitamin D - Rickets

Deficiency of vitamin C - Scurvy

Deficiency of vitamin B - Beriberi etc. 

A person who does not take proteins and carbohydrates in his diet for a long time, may become so lean that he will not be able to walk properly and his growth may also stop completely. This is because these two are the major nutrients for our body. 

Though water is not one of the five nutrients of balanced diet, but it is a major food component. Minimum water intake by a child should be 2 - 3 litres daily. 

High temperature cooking for longer duration results in the destruction of vitamin C, protein and mineral content of the food. Use of less water and cooking for shorter duration will result in preserving protein and mineral content of the food. 

Goiter - swollen neck glands

Scurvy - bleeding gums

Rickets - bow shaped legs

Beriberi - weak muscles and laziness 

Scurvy - Deficiency of vitamin C

Goiter - Deficiency of iodine

Rickets - Deficiency of vitamin D

Beriberi - Deficiency of vitamin B.