Science Study Notes on Food & Nutrition

By Neha Joshi|Updated : July 9th, 2020

According to eating habits of the animals, we classify them into three categories:

  1. Herbivorous: Those animals which only eat plants. Example – goat, cow, horse, etc.
  2. Carnivorous: Those animals which only eat animals are known as Carnivorous. Example lion, tiger, wolf, etc.
  3. Omnivorous: Those animals which eat both plants and animals. Example – bear, dog, etc.

Depending on the eating habits, there are different sources of food for different animals.

There are six significant components of food called nutrients that are necessary to have in the diet for healthy growth.
These are

  • Protein
  • Vitamins
  • Minerals
  • Fats
  • Carbohydrates
  • Water.

Components of Food

Nutrients are the chemical compounds present in our food which are necessary for the proper functioning of the human body.

There are six types of nutrients -


Carbohydrates are essential for our bodies as they are one of the three macronutrients. They are the primary source of energy for the human body.

Functions of carbohydrates: Carbohydrates provide the body with the energy it needs and is a good source of many vitamins and minerals.

Dietary fibre is a type of carbohydrate that cannot be digested by our bodies’ enzymes. It is found in edible plant foods such as cereals, fruits, vegetables, dried peas, nuts, lentils, and grains.

Sources: Fruits, Vegetables like potatoes, dairy products, etc. are the primary source of carbohydrates.


Proteins are also macronutrients and are necessary for building our bodies. They are essential for muscle development and growth.

Functions of Proteins: The human body uses protein to build and repair tissues. It also uses protein to make enzymes, hormones, and other body chemicals.

Sources:  lean meat, poultry, fish, eggs, etc. They are also present in dairy products like milk, yoghurt, and cheese. Seeds and nuts.


Fats are one of the three main macronutrients, along with carbohydrates and proteins. They are essential as the body uses fat as a fuel source, and fat is the primary storage form of energy in the body.

Functions of Fats:

Dietary fats are essential to give your body energy and to support cell growth. They also help protect your organs and help keep your body warm.

Sources: Avocadoes, fatty fish, whole eggs, etc.


A mineral is a chemical element required as an essential nutrient by organisms to perform functions necessary for life.

Functions of Minerals:

 Minerals help your body grow, develop, and stay healthy. The body uses crystals to perform many different roles from building strong bones to transmitting nerve impulses.

Sources: Brazil nuts, cashew nuts, cheese, eggs, milk, chicken, etc.


Water is defined as an essential nutrient because we require in amounts that exceed the body's ability to produce it.

Functions of water:

The body is made up of 50 to 75 per cent water. Water forms the basis of blood, digestive juices, urine, and sweat, and is contained in lean muscle, fat and bones.

Vitamins :

Vitamin word comes from two words Vital+Amines, so vitamins are vital amines needed by our body for proper growth. Vitamins are essential as they maintain a healthy metabolism.

Casimir Funk coined the term vitamin in 1911.

Vitamins are classified into two categories based on solubility type :

  • Water-soluble vitamins
  1. Vitamin C
  2. Vitamin B(Complex)
  • Fat-soluble vitamins
  1. Vitamin D
  2. Vitamin K
  3. Vitamin E
  4. Vitamin A

Water-soluble Vitamins :

Vitamin C: Vitamin C is also known as Ascorbic acid because of its ability to treat scurvy disease.

Functions of vitamin C:

  • It helps in the maintenance of cartilage, bones, and teeth.
  • It is helpful in wound healing.
  • It is crucial as it maintains the stability of the immune system.
  • The deficiency of Vitamin C can result in hollow bones.
  • The deficiency of Vitamin C in children leads to chest pain.
  • It is crucial as it helps in the absorption of iron.

Sources of Vitamin C:

It is found in abundance in sour and juicy fruits like lemon, guava, oranges, etc.

It is present in small amounts in milk and meat.

Vitamin B:

Vitamin B(Complex) is a group of vitamins collectively known as vitamin B complex.

Vitamins of this group are :

Vitamin B1: Also known as thiamine due to the presence of sulfur. Donth and Jackson extracted it in 1926 from the upper layer of rice.

Functions of Vitamin:

  1. It helps in the metabolism of carbohydrates.
  2. It helps in maintaining the appetite as digestive muscles require it.
  3. The nervous system needs to function correctly.

         Sources: It is found in cereals, pulses, yeast, dry fruit, meat, fish, etc.

Vitamin B6: It is also known as pyridoxine as it was synthesised by stiller in 1939. It adds to the pyridoxine, co-enzyme which acts as a vitamin. 

Functions of Vitamin:

  1. Responsible for maintaining healthy RBC and neurodegenerative.


It is present in the liver, meat, dry yeast, etc.

Vitamin B12:

It is known as cobalamin and is involved in every cell of the human body.

 It is the largest and most structurally complex vitamin.

Functions of the Vitamin:

  1. It helps in the metabolism of the protein.
  2. It helps in the production of blood cells in the bone marrow
  3. It helps maintain metabolism.

Sources: It is found in liver, egg, fish, etc.

Fat-Soluble Vitamins:

Vitamin A: Also called retinol. This vitamin is related to chlorophyll, green plants, and vegetation.

Functions of Vitamin:

The deficiency of vitamin A results in night blindness.

It is responsible for the maintenance of epithelial tissues.

Lack of Vitamin A leads to a disease called Keratomalacia.

  1. It helps in mucous secretion, which helps in stabilising the tissues.


  1. It is found in red and yellow vegetables.
  2. It is available in abundance in fish liver oil.

Vitamin K:

It is responsible for blood clotting. Vitamin K is not used as a dietary supplement. Vitamin K is a group of vitamins, i.e. K1 and K2.

K1 is obtained from leafy green vegetables, whereas K2 is obtained from meat.

Vitamin E:

Vitamin E is a must for healthy eyes, hair, and skin.

Functions of Vitamin E

  1. Vitamin E develops fertility.
  2. Lack of Vitamin E leads to sterility.
  3. Lack of Vitamin E stops the production of sperm.
  4. It helps maintain the healthy growth of RBC.

Sources: It is available in nuts like almonds, hazelnut, etc.

Vitamin D:

Vitamin D is present in very few food materials. It is also obtained from sunlight as sunlight triggers vitamin D synthesis.

Functions of Vitamin D:

  1. It is essential as it helps in the absorption of phosphorus and calcium.
  2. It is vital for human growth.
  3. It protects humans from the pox.
  4. It maintains the functioning of the parathyroid gland function.

Sources: These are present in fatty fishes like tuna, dairy products, etc.

Balanced Diet:

A diet is all that we consume in a day. And a balanced diet is a diet that contains an adequate quantity of the nutrients that we require in a day. A balanced diet includes six primary nutrients, i.e. Fats, Protein, Carbohydrates, Fibre, Vitamins, and Minerals.


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Posted by:

Neha JoshiNeha JoshiMember since Aug 2019
Postgraduate in Biophysics, Writer and Art Enthusiast
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Kumar Seenu

Kumar SeenuFeb 21, 2021

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Pleas juniyer supertet ki science ques dLi

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Kamboj BhaiNov 25, 2021

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