Balanced Diet, Classes of Food and their Importance

What is Balanced Diet?

A balanced diet is a meal containing all the six classes of food in their right and appropriate proportion needed for bodily growth and development.

The six classes of food required in a balance diet are carbohydrates, protein, fats and oils, mineral salts, vitamins and water; and these are required at varying percentages by the body. The percentage of nutrients required by the classes of food in a balanced diet is shown below:

• Carbohydrates: 60%

• Protein: 15%

• Fats and Oils: 15%

• Vitamins, Mineral salts and Water: 10%

Recall that a diet refers to the various types of food that a person eats often. Such diet is expected to contain the various food nutrients in their appropriate proportion for growth and development. A balanced diet is a type of healthy diet which provides the body with all the necessary nutrients required to function optimally.

A healthy diet refers to a diet which gives the body the right mix of nutrients. It will include whole grains, healthy proteins, lots of fresh fruits, and vegetables; while keeping sugars, salt, and bad fats low. 

Please read an introduction to nutrition, types and classes of food here.

Classes of Food

The six classes of fod that make up a balanced diet are summarized below:

1. Carbohydrates: These are the preferable and first source of energy to the body when digested and absorbed. They include energy-giving foods like rice, maize, yam, cassava, garri, bread, custard, etc.

2. Proteins: These are body-building foods required for cell growth and repair of worn out tissues. Examples include beans, eggs, cowpea, fish, meat, milk, etc.

3. Fats and Oils: These are food that contain high calories of energy (even more than carbohydrates), but are not directly used as energy source. They are rather preferably used as reserved energy. Examples are palm oil, groundnut oil, margarine, olive oil and butter.

Please read more on the composition and functions of the classes of food here.

4. Vitamins: These are natural organic substances needed by the body to grow and develop properly. There are 13 essential vitamins, split into two main groups. These are the fat-soluble vitamins (which are preserved in the body), and water-soluble vitamins (which dissolves in water, and can be eliminated through urine). Fat-soluble vitamins are put under the acronym ADEK, and water soluble vitamins, B and C.

Below are the fat-soluble vitamins, their sources and functions:

• Vitamin A: Helps us to see better at night. It also builds the skin and immune system. It is present in carrot and eggs.

• Vitamin D: It build bones by aiding the absorption of calcium in the small intestine. It is made by morning sunlight which acts on the skin. It is also present in foods like fatty fish, egg yolk and cod liver oil.

• Vitamin E: It functions to protect the cell, and can also enhance reproduction. They are present in green vegetables, seeds and nuts.

• Vitamin K: They prevent excessive blood loss from cuts and wounds by promoting blood clotting. They are found in in foods like broccoli and spinach.

You can read on the concept of food here.

Below are the water-soluble vitamins, their sources and functions:

• Vitamin C: They prevent gum diseases, keep the teeth healthy and promote wound healing.They are found in oranges, grapes and lemon.

• Vitamins B: These water soluble vitamins are put into vitamin B complex which include the following:

• Vitamin B1 (Thiamine): It supports proper functioning of the heart and nerve. It also aid in the conversion of digested food into energy.

• Vitamin B2 (Riboflavin): It acts as an antioxidant, promoting the breakdown of fats and ATP production.

• Vitamin B3 (Niacin): It boosts healthy skin and promote cellular metabolism.

• Vitamin B5 (Pantothenic Acid): It is needed in the formation of hormones by endocrine glands. It also assists in obtaining energy from food.

• Vitamin B6 (Pyridoxine): It assists in erythropoesis, that is, the formation of erythrocytes (red blood cells). It also promotes immunity and brain development.

• Vitamin B7 (Biotin): It assists in carbohydrate and lipid metabolism. It also assists in the development of healthy hair.

• Vitamin B9 (Folate or Folic Acid): It is important in cell division and DNA formation. It also aid in the development of the brain and spinal cord during pregnancy.

• Vitamin B12 (Cobalamin): It promote brain function, erythrocyte formation and DNA synthesis.

Note: B-complex vitamins are present in a variety plant and animal foods. They include meat, fish, eggs beans, vegetables, milk, whole grains, etc.

Please read on family health and personal cleanliness in basic science here.

5. Minerals: These are electrovalent compounds comprising of ions like Ca²⁺, Na⁺, Cl^-, and SO₄^2-. The various minerals have their respective functions; for instance, calcium is required in building strong bones and teeth, while iron is very important in the formation of hemoglobin in red blood cells.

Please read facts on red blood cells and hemoglobin here.

6. Water: It comprises of the elements hydrogen and oxygen in the ratio 2:1. It regulates body temperature, aids digestion of food, transportation of digested food, and elimination of waste products like urea.

Note: Roughage (Dietary fiber) is not often included in the six classes of food since they aren't absorbed into the bloodstream; rather, they add bulk to the contents of the large intestine, consequently aiding bowel movement and constipation prevention.

Please read on the characteristics of living things in basic science here.

Importance of Balance Diet

1. It supplies the body with all the nutrients necessary for its normal growth and development.

2. It helps prevent illness by enhancing the body's immune system.

3. Balanced diet prevents malnutrition and deficiency diseases like scurvy, beriberi, rickets, night blindness, goiter and kwashiorkor.

4. It provides immediate and reserve energy required for normal bodily activities.

5. Regular eating of balanced diet enhances nervous function (brain and spinal cord), thus improving cognitive activities, and overall mental health.

Please read the next topic (teeth and dentition) here.

Please read basic science scheme of work for jss1, first term here.