Dietary Macronutrients – Nutritional Components of Food


Health as defined by the world health organization (WHO) is defined as the state of complete physical, mental, and social well-being and not merely the absence of disease and infirmity. The knowledge of food and nutrition has a direct influence in maintaining good health of an individual.

Food is a complex mixture of various substances, which help:

  • To provide sufficient energy & heat for the various activities & body work.
  • In growth, repair & maintenance of body tissues.
  • In adding bulk to the diet to keep the digestive system, work well.

Nutrition is the science of foods which deals with the dynamic process in which the food consumed is digested, nutrients are absorbed, distributed to body tissues for utilization & wastes are disposed off the body. Nutrients are the constituents in food that must be supplied to the body in suitable amounts.

In addition, to acquire a sound health one must include a daily routine of consuming a balanced diet consisting of all the food groups and vital components in appropriate quantities.

The dietary components of food are:

  • carbohydrates
  • proteins
  • fats
  • minerals
  • vitamins
  • dietary fiber
  • water

Moreover, these are broadly classified into three groups:

  1. Energy giving: it comprises of carbohydrates & fats, which provides us with most of our energy required.
  2. Body building foods: these are rich in proteins & are involved in growth & repair of body cells.
  3. Protective foods: these are rich in vitamins & minerals & are involved in building up the body’s immune system.

Now let us briefly know that why all these components are so important & what all functions they perform.

These form the main bulk of diet & are the chief source of energy. They play an important role in metabolism of fats & in forming protein structures (non-essential amino acids)
It includes the sugars & starches.

  • Candy, soft drinks, sweets, desserts contain lots of sugar.
  • Bread, breakfast cereals, potatoes, & rice contain starch.

In a balanced diet, 60% of our daily calorie requirement should come from carbohydrates. However the amount can vary from 50%-70%.

These are more concentrated source of energy than carbs. However, amount should be in limit as high intake can lead to many harmful diseases in the long run.

If taken in appropriate amount body fat serves as a source of quick energy in times of starvation or fasting. Furthermore, it is required for the absorption of vitamins A, D, E & K.

  • It gives flavor & taste to the food.
  • It provides a cushioning support to our internal vital organs.
  • It provides essential fatty acids (EFA) which helps in reducing blood cholesterol, promotes growth, & maintains skin integrity.

When products include hydrogenated oils/trans fats it means that the amount of EFA in these products is greatly reduced and these should not be consumed on a daily basis. Fats can be obtained from butter, whole milk, oils, fish, nuts& seeds, ice-creams etc. nuts & seeds & fishes are rich sources of EFA’s. The fat in a balanced diet should provide 20-25% of total energy (i.e. 10-20gms). However, young children can utilize & need extra amount of good fats.

Like carbs & fats these also provide energy but due to the presence of nitrogen in their structure they perform one of the most vital functions needed for a healthy life i.e. for building up of body’s cells & tissues & for repairing & maintaining the worn out tissues. It also helps in synthesis of antibodies, enzymes, & hormones.

Animal sources of proteins are of better quality are readily absorbed & utilized by the body. These include milk and milk products, eggs, meat, poultry, fish, liver & an exception is soybean, which is a plant source. Plant sources include cereals, pulses, dry fruits, nuts, beans etc.

Daily requirement of protein is 1g/kg body weight. For e.g. A normal adult man of 60kg will require 60gm of protein. However, in stage of growth or illness requirement is increased.

These are required in very small amounts but are important for our growth & development. They make enzymes, which help to progress our body’s chemical reactions. They should be regularly consumed as their deficiency can lead to diseases such as night blindness, scurvy, pellagra, etc.

There are fat-soluble vitamins (A, D, and E&K) and water-soluble vitamins (B-complex & C). Chief sources include vegetables & fruits & our diet should include these in most of our meals.

These are also needed in small amounts but are important for our body’s basic growth & structure. There are some 50 minerals in our body serving important functions like formation of bones & teeth, formation of blood, hair growth, nail growth, skin integrity etc. Food sources include – egg, meat, milk, cheese, nuts, vegetables, beans, banana, orange, melons, salt etc.

Dietary Fiber
It is a type of carbohydrate found in vegetables, fruits, & whole grains, which absorbs water & increases bulk of intestinal contents & helps in intestinal movements. Its deficiency leads to constipation. It also lowers cholesterol & helps in weight reduction.

Though not a food, it is an important component of our diets. It is required for our basic metabolism as serves as a medium for all chemical reactions, maintains our body’s temperature, helps in nutrition processes etc. A 10% loss of water can lead to dehydration & a 20% loss may even lead to death. A daily diet is not complete without consumption of 8-10 glasses of water.

Health is often taken for granted, & its value is not fully understood until it is lost. So don’t be losers & have a healthy life with a balanced diet!


About Author

Anshul Jaibharat

I joined a diploma course in health nutrition and dietetics from the VLCC institute in North Africa, which is one of the brand names in the weight management industry. It is my goal to achieve success in the field of weight management and nutrition. See my profile page for more information!

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