Diet is the sum total of all nutrients we consume on a daily
basis. The three major macronutrients which we consume generally are carbohydrates,
fats and proteins.
The fats we
consume are first broken down into free fatty acids and glycerol, now these
have two pathways:
1. They are
used in the general metabolism of the body and provide the maximum amount of
ATP when compared to other macronutrients when they undergo complete beta
oxidation and go through citric acid cycle.
2. The excess
fatty acids go into the free fatty acid pool and these are converted into fat
for storage by lipogenesis.
These fat stores can be converted into fatty acids and
returned to the free fatty acid pool, when required by lipolysis.
we consume are first broken down into glucose and normal range of plasma
glucose is maintained in our body which varies depending on our intake of the
same, apart from that the following routes can be taken up by glucose in our
1. Some amount
of glucose goes into use in the general metabolism of the body by the process
of glycolysis which generates ATP and NADH for use in our body. Brain
metabolism exclusively uses glucose for its metabolic processes.
2. Some amount
of glucose is excreted in the urine which is around 0 to 0.8 millimoles/litre.
A higher amount of excreted glucose in urine is an indication of certain
pathological conditions like Diabetes mellitus.
3. In animals,
excess glucose in the body is stored in the form of glycogen by the process of
glycogenesis, which can be broken down into free glucose and released into
circulation by the process of glycogenolysis as and when needed by the body.
4. More excess
glucose in the body maybe stored as fat by the process of lipogenesis.
The proteins we consume in our diet are
absorbed in our body after being converted into amino acids and can have the
following fates in the body:
1. Mostly the
amino acids are used in synthesizing various proteins in the body.
under certain conditions of low glucose levels in the body, the amino acids can
be used to produce glucose by the process of gluconeogenesis.
a normal human body, the first and preferred source of energy are the
carbohydrates, followed by fats and then the proteins. Breakdown of proteins
for glucose and hence energy, occurs in extreme starvation conditions and also
in certain diseased conditions like Kwashiorkor.
a balanced diet by taking the right proportions of each of the above mentioned
macronutrients along with the essential micronutrients is important for a
healthy and well-functioning body.