What is Food?
The word “food” brings to mind countless images. We hear this word daily, yet we don’t fully understand its value and function. Food is associated with worship and divinity, celebration and mourning, family gatherings, and community feasting. For example, birthday cakes are shared with friends and family to celebrate milestones, and special dishes are prepared for festivals and religious ceremonies. During times of mourning, communities may gather and bring food to offer comfort. Food is closely interwoven with every aspect of our existence. This is not surprising, because food plays a crucial role in our lives. It sustains us and nourishes us. It is the life-giver.
The term food refers to anything that nourishes the body. Food is the fuel of our bodies. Just like a car needs fuel to run, our bodies need food to stay alive, grow, and have energy to do things. It includes solid, semi-solid, and liquid foods that can be consumed to sustain the body and keep it healthy. Solid foods are items like bread, rice, fruits, and vegetables. Semi-solid foods include items such as yoghurt, pudding, and mashed potatoes. Liquid foods include milk, juice, and soup.
The Relation Between Food and Our Body
Food is a basic necessity. Food is essential because it contains substances which perform important functions in our body. These essential substances contributed by our food are called nutrients. If these nutrients are not present in our food in sufficient amount, the result is poor health and, in some cases, even death. Food also contains many substances which are non-nutrients, e.g., colouring and flavouring substances in food. It is any substance consumed to provide nutritional support for the body. It is a complex mixture of nutrients and non-nutrients. Food comes in solid and liquid forms and can be consumed to sustain the body and keep it healthy.
FUNCTION OF FOOD
This is a fact that food consists in part of various nutrients. We may be surprised to know that there are over 40 essential nutrients which are supplied by the food we eat. (Morris & Mohiuddin, 2023) These nutrients can be classified into five major categories(based on certain similar features): Proteins, carbohydrates, fats, vitamins, and minerals. Water is important as both a nutrient and a food.
Each nutrient category has a specific physiological role. Here, the term “physiological role” refers to food’s role in maintaining specific bodily functions. (Morris & Mohiuddin, 2023) Food also has social and psychological functions in addition to physiological ones. (Bellisle et al., 1998, pp. 173-193)
So, mainly three categories are the functions of foods
- Physiological function
- Social function
- Psychological function
Physiological Function
The physiological functions of food are energy-giving, body-building, protective, and regulatory. (Medicine et al., 2023) We need energy every moment of our lives for performing various activities such as sitting, standing, walking, running, and carrying out all our household and other tasks. We may not be aware of it, but several activities take place within the body. For example, the beating of the heart, contraction of the intestines, and expansion and contraction of the lungs. Activities performed within the body also require energy expenditure.
Energy-giving Food
The energy-giving function of food is basically performed by two nutrient categories: carbohydrates and fats. This is why these nutrients are also referred to as the “body fuels”. (Bhupathiraju & Hu, 2025) This is similar to burning coal or wood, which are familiar fuels. When these fuels are burned, energy is released in the form of heat and light. The fire we observe is, in fact, nothing but the conversion of the energy locked up in the fuel to heat energy and light energy. Similarly, carbohydrates and fats are burned in the body. The energy that these substances contain is released to perform the various activities.
Body-building Food
Food is also needed for growth and repair. Do you know what is meant by these two terms, growth and repair? As we know, our body is made up of millions of units called cells. The existing ones also increase in size; on the other hand, cells get worn out and die. These cells have to be replaced. This process is called repair. For both growth and repair, proteins are necessary; this helps us understand the role of proteins in growth and development. (Protein in diet, 2023) If we just think of the tremendous increase in height and weight that occurs from infancy to adulthood. How does this take place? This is made possible by the process of growth.
Protective Food
The other major physiological functions performed by food are protective and regulatory. Let us first know the meaning of the term protective. Here, protective refers to the role in preventing infection by ensuring proper functioning of the body systems responsible for fighting infections. Even if a person develops an infection or another type of illness, food and the nutrients it contains facilitate rapid recovery. A person on a poor diet would take much longer to recover. He would get ill more easily as well.
Regulatory food
The regulatory function mentioned earlier refers to the role of food in controlling body processes. As we are aware, several processes take place in the body, such as the beating of the heart, maintenance of body temperature and contraction of muscles. Each of these processes is controlled; for example, our body temperature is maintained at 98.4°F (37°C). Similarly, the rate at which the heart beats is also maintained; this is achieved by certain specific nutrients, among other substances, and illustrates their regulatory function. Vitamins, minerals, and proteins contribute to both protective and regulatory functions, as does water
We are also probably aware that several chemical reactions take place in the body. With the aid of these chemical reactions, simpler substances are used to build more complex ones. Similarly, complex substances are broken down into their simple component. The figure below shows how one or two types of simple units join to form complex substances and how complex substances break down into their simpler units. The rate at which these reactions proceed is carefully controlled according to the needs of the body. Vitamins, minerals, and proteins play a major role in controlling these reactions; they act as regulators. (Morris & Mohiuddin, 2023)
Social Function
Food and eating have significant social meaning. Sharing food with any other person implies social acceptance. When we share a meal with anyone else, we are expressing our acceptance of friendship and respect for that person. Earlier, only persons enjoying equal status in society ate together. A person would never share a meal with someone inferior to him in social terms. Of course, we observe considerable change in these respect now, particularly in cities and towns; for example, in a restaurant, any person can eat irrespective of their social background if they have the money to pay for the food.
Food is an integral part of festivity anywhere in the world. We noticed that on joyous occasions such as the birth of a child or a marriage are celebrated by having feasts and serving delicacies. Festivals such as Diwali, Dussehra, Pongal, Onam, Lohri, Holi, Christmas, and Eid are celebrated with special, prescribed menus; in all these cases, food serves the function of bringing people together.
Food also has specific significance and meaning in religious contexts. Certain food items such as fruits, sweets, and coconuts are offered to the deity in temples. Often sweets are prepared at temples and gurdwaras and distributed to devotees as a benediction or Prasad. Further, people of a given religious community share a common eating pattern. This is because religious texts and practices strongly recommend some foods while rejecting others. Food thus becomes an integral part of the social and religious life of people.
Psychological Function
We all have emotional needs such as the need for security, love and attention. Food is one way through which these needs are satisfied. When a mother prepares her child’s favourite dish, the child recognises that she loves him enough to remember his likes and dislikes. He appreciates the attention he is given. As we are aware, when people share food, it serves as a token of friendship and acceptance. A child quickly accepts foods eaten by his friends, and by people he admires or wants to identify with. for example, if a kid doesn’t like to eat vegetables, but he sees his favourite sports person eat a sandwich loaded with veggies, he also likes to eat this type of sandwich. He may even accept food he first found distasteful if he observes his friends enjoying it. Sharing the same food as others around him and those he considers important in his social sphere gives him a degree of confidence in himself and reassures him that he will be accepted by others like him.
Food is also closely allied to our emotions. Food often serves as a reward when a mother wishes to reward her child for doing well in a test; she may buy him a sweet or an ice cream. In this manner, that particular food item evokes a pleasant feeling in the mind of the child. On the other hand, certain foods become associated with sickness, such as khichdi (a rice-dal porridge) these type of food is generally eaten when a person suffers from fever and may, therefore is not associated with pleasant feelings.
References:
Bellisle, F., Blundell, J. E., Dye, L., Fantino, M., Fern, E., Fletcher, R. J., Lambert, J., Roberfroid, M., Spectre, S., Westenhöfer, J. & Westerterp-Plantenga, M. S. (1998). Functional food science and behaviour and psychological functions. British Journal of Nutrition 80(1), pp. 173-193. https://doi.org/10.1079/BJN19980109
Medicine, N. A., Division, H. a., Board, F. a. & Energy, C. o. (2023). Dietary Reference Intakes for Energy. National Academies Press. https://www.ncbi.nlm.nih.gov/books/NBK591034/
Bhupathiraju, S. N. & Hu, F. (November 1, 2025). Carbohydrates, Proteins, and Fats. Merck Manual Consumer Version. https://www.merckmanuals.com/home/disorders-of-nutrition/overview-of-nutrition/carbohydrates%2C-proteins%2C-and-fats?query=brown+fat
(2023). Protein in diet. MedlinePlus Medical Encyclopedia. https://medlineplus.gov/ency/article/002467.htm
Morris, A. L. & Mohiuddin, S. S. (2023). Biochemistry, Nutrients. NCBI Bookshelf. https://www.ncbi.nlm.nih.gov/books/NBK554545/