Classes Of food

Different food substances play different role in human body.Human body needs several different kinds of food substances to keep ourselves healthy. The food that we take may be classified as following;

• Carbohydrates 
• Fats
• Protein
• Vitamins
• Mineral salts
• Water

Carbohydrates
Carbohydrates are the compounds containing carbon, hydrogen and oxygen. e.g, glucose, cane, sugar, starch etc.Foods containing sugar, honey, fruits,jams or foods containing starch such as, rice maize, potato, bread, biscuits, and flour are rich in carbohydrates.  The carbohydrates are the main source of energy.

Fats:

Fats are the compounds that contain carbon, hydrogen, and oxygen but proportion of hydrogen is higher than others.Cashew nuts, ground nuts, kernel, cheese, coconut, butter, cream are the foods that are rich in fats. Fats are not only the source of energy for the body, but, the fats stored under the skin also helps to insulate the body against heat loss.. These are especially important to people living in the cold climates. 

Proteins:

Proteins are the compounds containing carbon, hydrogen, oxygen and nitrogen. Phosphorus and sulfur are  also present in proteins.  Lean meat, fish, milk, cheese and eggs are rich in animal proteins.therefore, peas,  beans, groundnuts and cashew nuts are rich in plant proteins. proteins plays an important part in growth and repairing process of worn out parts of body. Deficiency in proteins may lead to the kwashiorkor   disease in children. such children suffer from an enlargement of liver, changes in pigmentation of skin and hair, and general drowsiness.

Vitamins:

Vitamins are substances required by animal and human for health. Lack of vitamin in diet may result in deficiency disease. There are different types of vitamin, Vitamin A, Vitamin B, Vitamin C, Vitamin D and vitamin K.  It should also be noted that some of vitamins if taken in excessive amounts, may be harmful to body.  Large quantities of vitamin tablets are not suitable except medical advice.

Mineral Salts:

Mineral salts provide other elements besides, carbon, hydrogen, and oxygen, according to the need of body for proper growth and development.

Water:

Water makes up the main part of living bodies. About two third of the weight of human body is consist of water.Usually a man can survive a longer period without solid food but can not survive without water.Many chemical reaction that take place in human body need water. Water is solvent for many food substances.

Other than this water is also needed to maintain body temperature in hot seasons. A body lose a great amount of water in urine, breath and sweating. Therefore,  we need to drink  a sufficient amount of water or food containing more water such as, leafy vegetables and juicy fruits, so that , we can balance the amount of water in our body.