The role of diet in Health, Nutrition and Fitness
During pregnancy the mother must increase energy intake. During
lactation, energy intake is also increased. A steady balanced diet is
essential, in the right quantities, throughout life, to maintain healthy growth
and development. The first part of this two part article looks at the
background to nutrition and the digestive process. Part two will conclude
with the role of diet from pre-conception to old age.
Even before pregnancy, diet plays an essential role in preparing the female
body for a normal and healthy birth. Vitamin D deficiency could cause
pelvic deformation, where normal delivery of child would be difficult.
Vitamin B12 deficiency could cause infertility and a history of dieting would
deplete any nutrient reserves in the body, giving rise to infertility and
reduction of nutrients for the foetus.
A diet consists of nutrients. Nutrients are classed as macro, required in
large quantities and micro, required in small quantities. Macro nutrients
include carbohydrates, proteins and lipids (fats). Micro nutrients include
vitamins and minerals. Another product essential for a diet is water. Water
is required in large quantities to aid metabolism, which occurs in an
aqueous environment.
Bread, cereals and potatoes contain carbohydrates, non-starch
polysaccharides (nsp), water, vitamins and minerals.
It is important to have an appropriate amount in the diet for the following
reasons:
Carbohydrates provide energy, which is essential for all metabolic
processes within the body, including mechanical movement, respiration,
growth, repair, cell metabolism, DNA replication, vision, transport within the
body and maintaining homeostasis (constant internal body equilibrium such
as constant blood pressure, body temperature, breathing rate, pulse rate).
Glucose (broken down from carbohydrates) is also required for brain cells
and the central nervous system.
NSP's (fibre) are particularly important in a diet because they act as
roughage or bulk. The nsp's are not digestible and therefore pass straight
through the digestive system. However, because of the increase in the bulk
of food, it passes through the system more quickly than if nsp's were not
digested. NSP's ensure food is not left in contact with the gut lining for
prolonged periods of time, which could have serious health effects,
including cancer.
Meat, fish, pulses contain protein, water, minerals and vitamins, nsp's (in
pulses) and lipids.
Proteins exist in two states, fibrous and globular.
Fibrous proteins have a structural role, eg tendons, ligaments, hair, growth
and structure. Globular proteins function as enzymes which allows cell
metabolism to occur, help in our immune system by producing antibodies
to fight diseases and aid transport, both intra and extra cellular. They also
work as hormones, and for growth and repair of body tissues and in blood
clotting. Too much protein in our diet is removed as waste material; too
little protein in our diet could result in muscle wasting and such diseases as
marasmus and kwashiorkor.
Protein constitutes 12-18% of the body's mass.
Milk and dairy products contain protein, lipids, water, vitamins and
minerals.
Fat and sugar contain carbohydrates, water, lipids, minerals and vitamins.
Lipids are broken down into glycerol (a further source of glucose) and fatty
acid, including essential fatty acids.
The essential fatty acids are components of the body's cells, especially in
the formation of cell membranes. Lack of fatty acids can affect blood
pressure, blood clotting and homeostasis. Excess fat, however, can be
stored in the body in adipose tissues and possibly result in obesity and
related health problems. Although, much obesity is the result of certain
gene deficiency, which will be discussed in more detail in a further article.
[ ... ]
