Nutritional Importance of Lipids

Lipids are organic compound containing carbon, hydrogen and oxygen only, they are insoluble in water but soluble in organic solvent such as Benzene, Chloroform, ethanol, petroleum ether, ethanol etc. Dietary lipid otherwise known as triglycerol are commonly known as fat & oil.

Fats are lipid from animal source. They are usually solid at room temperature but liquid above room temperature.

Lipid from plant source are known as oil.

Lipid can be saturated fatty acid or unsaturated fatty acid. They can be essential or non-essential.

Lipid generally contributes 15-30\% of the energy requirement of the body. Other major lipids in the body except triglyceride include: cholesterol and phospholipids.

Major nutritional function of Lipids

Dietary lipid has two major nutritional functions:

* It supplies triglycerides that normally constitute 90-95\% of dietary lipids which is a concentrated source of fuel to the body.

* It provides essential fatty acids which are components of fat soluble vitamins (e.g. ADEK)

Essential Fatty Acids (EFA)

Essential fatty acids are dietary lipids that the body cannot synthesize, they can only be gotten from dietary source, they can be abbreviated as (EFA). e.g. includes: Linoleic, Linolenic and Arachidonic acid.

It should be noted that the arachidonic acid can be synthesized from the linoleic acid in some animal species including man.

However the conversion efficiency of linoleic acid to arachidonic acid is not clearly known in man.

Functions of EFA

* EFA is the structural component of the biological membranes.

* EFA participate in the transport and utilization of cholesterol.

* It prevents fat accumulation in the liver.

* It is required for the synthesis of prostaglandin.

* It maintains proper growth and reproduction of the organism.

DEFICIENCY OF EFA ⚠️

* Impairment in growth and reproduction.

* Increase BMR (Basal Metabolic Rate).

* Scaly dermatitis, it is also called toad skin or phrynoderma.

Sources of essential fatty acid (EFA)

Essential fatty acid are common in vegetable oil and fish oil.

The rich vegetable sources includes:

*Sun flower oil

* Corn oil

* Cotton Seed oil

* Soya beans oil

These essential fatty acid are also known as PUFA (Poly-unsaturated fatty acid).

The fat of animals origin contains less PUFA with the exception of fish oil.

Typical example includes:

Butter, fat of meat, Pork and chicken.