Nutrition Meaning and Classification of Food Based on Nutritional Values

Each and every item of food that we consume have some nutritional values. They provide nourishment to the body and help in the growth of the body and also protect us from disease and decay. In this article, we are going to understand What is Nutrition and Nutritional Value. And also a study of the classification of various nutrient elements inherent / involved in our food according to those nutritional values.

Nutrition
Nutrition is defined as the process of nourishment or providing/intake of food to the body or organism. It can be defined as the sum total of acts or processes by which any living organism consumes and utilizes the food for growth and sustainability.

Nutrition, as a science, studies the interaction of nutrients and other chemical substances in our food which help in the maintenance and growth of our body besides aiding in digestion, excretion, and reproduction activities of our body.

Nutrient
A nutrient is any substance or ingredient of food that is used for the maintenance of life and growth of any living organism.

Nutritional Value
The nutrients of each food are assigned some values by the nutritionists who use those figures to monitor the growth of a healthy body. These values are used to study their impact on health and for conducting researches on food ingredients for better monitoring of life and health. A Nutritional value indicates the composition of different nutrients in any food ingredient. Different types of food have different nutritional values.

Classification of Food Based on Nutrients

All our food items have been classified into seven groups based on their nutritional values.

1. Carbohydrates
2. Proteins
3. Fiber or Roughage
4. Fats
5. Vitamins
6. Minerals
7. Water

Now, these seven categories can again be grouped into Two Major Groups as Macronutrients and Micronutrients. 

Macronutrients

Macronutrients are those substances that are required in bulk quantities for the maintenance and growth of our body. They provide the energy required for the body which is used for metabolism and other functions of the body. These macronutrients are produced in our body itself by the digested food that we consume. This energy is measured in calories and is represented in nutritional facts as Kcal / per gram (in figures).

Macronutrients contain the following categories of nutrients which are required in abundance.

• Carbohydrates
• Proteins
• Fiber
• Fats
• Water

Micronutrients

Micronutrients are food components that are essential for the health and development of the body. They are found in very small quantities, unlike macronutrients which are found in abundance. These nutrients are directly derived from the food that we consume whereas macronutrients are produced in our body from the food.

Micronutrients are mostly known to be found in these below mentioned two categories

• Vitamins
• Minerals

Let us take a look at some salient features of all these above-mentioned nutrients. 

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7 Types of Nutrients

Carbohydrates

• Carbohydrates are small molecules that consist of carbon, hydrogen, and oxygen atoms, or particles.
• These carbohydrates are found in starch foods and sugars.
• Carbohydrates are broadly classified into simple carbohydrates and complex carbohydrates according to the number of sugar units they contain.
• Simple carbohydrates like sugar consist of one or two sugar units. They are derived from grapes, sugar canes, and milk sugars.
• Complex carbohydrates are rich in starch made up of multiple sugar units and they are found in rice, wheat, bread, noodles, cereals, and other grain foods.
• Carbohydrates are essential for stimulating insulin production in our body besides supplying the energy to our body. If glucose levels are not sufficient in the body, insulin production will become hindered and insulin is to be injected physically to maintain the normal levels.
• Metabolism and catabolism of the body are possible due to the presence of these carbohydrates in the bodies. Metabolism keeps maintenance and healthy functions of the body whereas catabolism refers to the excretion and extraction functions of the body.

Proteins

• Proteins are structural materials composed of nitrogenous molecules and amino acids that are essential for our body.
• They are large macromolecules containing nitrogen, oxygen, hydrogen, and sulfur along with amino acids.
• Proteins make up the structural components of our body tissues such as muscles, hair, etc.
• Some of the proteins act as enzymes and antibodies also.
• The amino acids aid in the production of new proteins that are most essential for our body.
• The proteins that we consume through food supply the amino acids which are used for new protein production by our body.
• As there is no provision for storage of proteins in our body structure, we need to eat protein content food daily to supply the nitrogenous molecules and amino acids to the body.
• Proteins are more essential in some special cases as during pregnancy, child growth, lactation, and healing during injuries to the body.
• Proteins are available abundantly in beans, cheese, beef, and other dairy products and meat products.
• Protein foods and powders are available in medical stores like Protinex, Prosure, Ensure and Nutrilite protein powder, etc. 

Fiber or Roughage

• Fiber is one more important nutrient for the body which controls the digestive process and keeps our body healthy.
• Fiber is a dietary material found in vegetables, fruits, whole grains and stems, and leaves of all plants.
• It is made up of cellulose, lignin (hard structure of plants), and pectin (soft structure of plants).
• Fiber is not easily or fully digestible as they are resistant to digestive enzymes. So, fiber aids in mixing up with the waste and thereby making the stools easily pass through the colon.
• Fiber can be either soluble with water or wholly insoluble. Insoluble fiber can be found in whole wheat, most green vegetables, some fruits, and nuts. Soluble fiber is found in oats, peas, and many fruits.

Fats

• Fat is an oily substance that generally deposits as a layer under the skin or around some organs of the body.
• Fats are also referred to as triglycerides. They are three fatty acid chains attached to the central glycerol of the molecule. The glycerol is a colorless, sweet, oily substance forming the base for fat.
• Fat is different from oil. Because oil is liquid at room temperatures whereas fats are solid.
• Fats are classified into two major groups as saturated fats and unsaturated fats.
• Saturated fats have each and every one of their carbon atoms in the fatty acid bonded with hydrogen atoms. So a molecule of saturated fat contains an equal number of carbon and hydrogen atoms in it.
• But, unsaturated fats have some of their carbon atoms double-bonded with hydrogen atoms. So, one hydrogen atom can get bonded with 2 or 3 or even more carbon atoms in these unsaturated molecules. Thereby, there will be lesser hydrogen atoms and comparatively more carbon atoms in an unsaturated fat molecule. 
• Many fats are essential for the body, though some of them may be unnecessary.
• Fats provide essential energy required for maintaining healthy cell functions in the heart, brain, and the skeletal muscles of the body. They also aid in the digestion of vitamins.
• Unsaturated fats like vegetable oils are more healthy for our bodies.
• Saturated fats get deposited in our bodies as layers (as they are highly insoluble). So, they should be avoided entirely.
• Omega-3 and Omega-6 are some essential fatty acids for our bodies.

Water

• Water is known as H2O. A water molecule contains two atoms of Hydrogen and one atom of Oxygen.
• Water is an essential part of our food.
• Most of the liquid from our body gets excreted in the form of urine, stools, and sweat. So, we should compensate for the dehydration by drinking water.
• The quantity of water to be consumed can vary from person to person and it depends on the food intake also. People accustomed to dry and hot foods require more water than others consuming cool and liquid foods.
• Men require more water than females normally. The recommended total liquid quantity as per recent researches by the European Food Safety Authority is 2.5 liters per day for males and 2 liters per day for females. The dosage includes water or liquids already present in the food we consume and the beverages like tea, coffee, milk, juices, or alcoholic drinks that are consumed. Some exceptions are there like pregnant women and breastfeeding women should take extra water to compensate for the extra requirements.
• Many chemical substances like iron, calcium, sodium, potassium, magnesium, sulfur, etc. are present in drinking waters.

Vitamins

• Vitamins are organic compounds essential for our body but in very limited quantities. These organic compounds can be either in gaseous, liquid, or solid forms containing carbon.
• An organic compound is called a vitamin when the body itself is unable to make that chemical compound on its own chemically in sufficient quantities. So, it needs to be supplemented through our food intake.
• Our daily food intake should contain these essential vitamins sufficiently to maintain a healthy body.
• Vitamins have various functions and act as hormones and antioxidants for regulating or stimulating blood cells and tissues into action or for helping enzymes in their work.
• Only 13 groups of vitamins have been recognized as vitamins and many other organic compounds are not included in vitamins such as some amino acids, minerals, and fatty acids which are also essential for the body.
• Vitamins are denoted with an Alphabet as its generic or collective title such as Vitamin A, Vitamin B, Vitamin C, Vitamin D, etc...

Minerals

• Minerals are inorganic chemical substances that are less common in our food.
• Minerals are classified into two groups as bulk minerals or trace minerals.
• Bulk minerals are more essential and they are recommended for a quantity of more than 150 mg per day. These minerals are also known as macrominerals.
• Other minerals that are not so much required are known as trace minerals. They are required in lesser quantities of less than 150 mg per day.
• Calcium, magnesium, sodium, potassium, phosphorous, and sulfur are examples of macro minerals.
• Zinc, copper, manganese, iodine, iron, nickel are examples of trace minerals.
• Iodine is comparatively more important and required in more quantities than other trace minerals.