HUMAN ADAPTATION TO FOOD AND NUTRITION
Food is the very basis of our life. It contains different
nutrients that are needed by the body for survival and
sustenance. The food we eat is digested and converted into
nutrients. These nutrients are absorbed and transported to
different parts of the body, and utilized for the day-to-day
functioning. At the end they are disposed of by further
metabolism and transformed into the end products. We need to
consume a variety of foods in order to remain healthy.
Thus, we can define food as any solid or liquid which when eaten
can supply any of the following:
Material from which the body can produce movement, heat or
other forms of energy,
Material for growth, repair and reproduction,
Substances necessary to regulate the production of energy or
the processes of growth and repair.
The components of foods which have these functions are called
nutrients. In other words, nutrients are vital in keeping a
living thing alive and helping it to grow.
The diet consists of those foods or mixtures of foods in the
amounts which are eaten daily. A good diet provides adequate
amounts of all the nutrients, without harmful excesses, from a
wide range of foods. Dietary habits are dependent on
geographical and cultural traits and vary accordingly.
Nutrition is the process by which living things receive the food
necessary for them to be healthy. The science of nutrition is a
study of all the processes of growth, maintenance and repair of
the living body which depend upon the digestion and absorption
of food and the study of that food.
FUNCTIONS OF FOOD
Physiological functions
The most important function of food is to build our body. We
have seen that we probably weighed somewhere between 2.5 to 3.2
kg at birth and now weigh between 45 to 60 kg. This growth is
the result of the food we ate from birth to adulthood. Now as
an adult, our weight is constant which shows that we have
achieved optimum growth. At this stage, the food we eat helps
to maintain and renew worn out cells of our body and keep the
body in good condition. Secondly, food provides the energy, our
body needs for all its activities, voluntary and involuntary.
We know that even when we sleep, many of our body's activities
continue, like breathing, heartbeat, digestion, absorption of
food, etc. These keep us alive without any effort on our part
and are called involuntary activities. The work or activities
we do when we are awake and our mind is in it like studying,
, walking, cooking or working at the desk, or playing a game of
badminton, is called voluntary activity. The amount of energy
we need for all these depends on the kind of activity and the
time and energy we spend doing it. The third function of food
is to regulate all the activities of the body and protect it
from diseases and infections. Examples of some of the activities
which regulate the body are given below:
Beating of our heart for circulation of blood
Maintenance of our body temperature
Muscle contraction for voluntary and involuntary movements
Removal of waste from the body in form of sweat, urine and
faeces, etc.
Apart from these, vital nutrients in food also help to protect
the body from various infections, diseases and from wearing out.
Psychological functions
In addition, to meeting our physical needs, food also satisfies
certain emotional needs. These include a feeling of security,
love and attention. We feel secure when familiar foods are served
which are also known as comfort foods. When a child comes home
from school the mother knows that he/she is hungry and serves
food. Thus, she expresses her love and attention. Many times,
we miss our mother because of the attachment to her cooking.
Socio-cultural Functions
We know how important food is in our social and cultural life.
We serve refreshments at meetings and seminars or to visitors
to create a relaxed atmosphere for an exchange of ideas. In most
of our festivals and celebrations we have lunch and dinner with
family and friends which binds us together. Food is also used
as an expression of happiness. For example, we distribute sweets
when we pass examinations, buy a car or when there is a marriage
feast. We also celebrate birthdays, anniversaries, promotions
etc. by cutting cakes and enjoying food at parties. In religious
functions like Bihu, Puja, Ramzan, Christmas etc. we make
special preparations to distribute food offerings. Thus, food
helps to strengthen our social and cultural ties.
HUMAN ADAPTATION TO FOOD AND NUTRITION
In the process of natural selection, those genes which are
adaptive to a given environment in terms of ingestion,
digestion, absorption and elimination of a particular food, are
favoured by nature in the process of evolution and helps the
great deal in the formation of human diet. Primary in the field
of three processes the genetic-environmental adaption is seen
with regards to food, i.e., a) Metabolism, b) Sensory perception
and c) Appetite control.
Food is the very basis of our life. It contains different
nutrients that are needed by the body for survival and
sustenance. The food we eat is digested and converted into
nutrients. These nutrients are absorbed and transported to
different parts of the body, and utilized for the day-to-day
functioning. At the end they are disposed of by further
metabolism and transformed into the end products. We need to
consume a variety of foods in order to remain healthy.
Thus, we can define food as any solid or liquid which when eaten
can supply any of the following:
Material from which the body can produce movement, heat or
other forms of energy,
Material for growth, repair and reproduction,
Substances necessary to regulate the production of energy or
the processes of growth and repair.
The components of foods which have these functions are called
nutrients. In other words, nutrients are vital in keeping a
living thing alive and helping it to grow.
The diet consists of those foods or mixtures of foods in the
amounts which are eaten daily. A good diet provides adequate
amounts of all the nutrients, without harmful excesses, from a
wide range of foods. Dietary habits are dependent on
geographical and cultural traits and vary accordingly.
Nutrition is the process by which living things receive the food
necessary for them to be healthy. The science of nutrition is a
study of all the processes of growth, maintenance and repair of
the living body which depend upon the digestion and absorption
of food and the study of that food.
FUNCTIONS OF FOOD
Physiological functions
The most important function of food is to build our body. We
have seen that we probably weighed somewhere between 2.5 to 3.2
kg at birth and now weigh between 45 to 60 kg. This growth is
the result of the food we ate from birth to adulthood. Now as
an adult, our weight is constant which shows that we have
achieved optimum growth. At this stage, the food we eat helps
to maintain and renew worn out cells of our body and keep the
body in good condition. Secondly, food provides the energy, our
body needs for all its activities, voluntary and involuntary.
We know that even when we sleep, many of our body's activities
continue, like breathing, heartbeat, digestion, absorption of
food, etc. These keep us alive without any effort on our part
and are called involuntary activities. The work or activities
we do when we are awake and our mind is in it like studying,
, walking, cooking or working at the desk, or playing a game of
badminton, is called voluntary activity. The amount of energy
we need for all these depends on the kind of activity and the
time and energy we spend doing it. The third function of food
is to regulate all the activities of the body and protect it
from diseases and infections. Examples of some of the activities
which regulate the body are given below:
Beating of our heart for circulation of blood
Maintenance of our body temperature
Muscle contraction for voluntary and involuntary movements
Removal of waste from the body in form of sweat, urine and
faeces, etc.
Apart from these, vital nutrients in food also help to protect
the body from various infections, diseases and from wearing out.
Psychological functions
In addition, to meeting our physical needs, food also satisfies
certain emotional needs. These include a feeling of security,
love and attention. We feel secure when familiar foods are served
which are also known as comfort foods. When a child comes home
from school the mother knows that he/she is hungry and serves
food. Thus, she expresses her love and attention. Many times,
we miss our mother because of the attachment to her cooking.
Socio-cultural Functions
We know how important food is in our social and cultural life.
We serve refreshments at meetings and seminars or to visitors
to create a relaxed atmosphere for an exchange of ideas. In most
of our festivals and celebrations we have lunch and dinner with
family and friends which binds us together. Food is also used
as an expression of happiness. For example, we distribute sweets
when we pass examinations, buy a car or when there is a marriage
feast. We also celebrate birthdays, anniversaries, promotions
etc. by cutting cakes and enjoying food at parties. In religious
functions like Bihu, Puja, Ramzan, Christmas etc. we make
special preparations to distribute food offerings. Thus, food
helps to strengthen our social and cultural ties.
HUMAN ADAPTATION TO FOOD AND NUTRITION
In the process of natural selection, those genes which are
adaptive to a given environment in terms of ingestion,
digestion, absorption and elimination of a particular food, are
favoured by nature in the process of evolution and helps the
great deal in the formation of human diet. Primary in the field
of three processes the genetic-environmental adaption is seen
with regards to food, i.e., a) Metabolism, b) Sensory perception
and c) Appetite control.
