Fats, Components of fats, dietary sources of fat, essential fatty acids, fat deficiency, and excessive intake of fat

Ayurveda for a healthy life ! – 44/2025 on 16.1.2025

FATS

1.  Components of fats

They are triglycerides, saturated fatty acids, unsaturated fatty acids, lecithins and cholesterol.

1A.   Triglycerides : Triglycerides are the most abundant lipids. 95% of food lipids are triglycerides. They are the esters of three molecules of fatty acids attached to glycerol.

1B.   Saturated fatty acids : Saturated fatty acids are derived from animals and coconut. Palmitic and stearic acid are saturated fatty acids. They can be synthesised in the body from acetates
by catabolism of carbohydrates and proteins.

1C.   Unsaturated fatty acids : Usually unsaturated fatty acids are liquid at room temperature and are obtained from vegetables, nuts or oil seeds. Polyunsaturated fatty acids cannot be adequately synthesised in the body.

1C 1.   Two families of polyunsaturated fatty acids are important namely,

A. Omega-6 fatty acids : Linoleic acid and arachidonic acid and

 B. Omega-3 fatty acids : Linolenic acid, elcosapentanoid acid (EPA) and docosahexanoic acid (DHA). These polyunsaturated fatty acids should be included in the diet to maintain good health. These are referred to as essential fatty acids.

1C 2.   Essential fatty acids : Essential fatty acids are important constituents of cell membrane. They act as mediators for precursors of prostaglandins, thrombohexane and leukotrienes. At least 3% of the caloric requirement of an individual should be derived from essential fatty acids. EPA and DHA lower blood cholesterol and triglyceride concentration. Eicosanoids play an important role in the regulation of lipid concentration, blood pressure, immune response and inflammatory response to injury and infection.

1D.   Lecithin : Lecithin is an important phospholipid. It is a major constituent of cell membrane. Lecithin can be synthesised in the body by the liver.

1E.   Cholesterol : Cholesterol is a lipid essential to maintain good health. It can be synthesised in the body from proteins, fats and carbohydrates. It is an important constituent of cell membrane. It is a precursor of Vitamin D and hormones. Cholesterol is found only in animal food such as eggs, liver, kidneys, cheese and ghee.

1F.   Circulating lipoproteins : Lipids in circulation are bound to proteins. This complex is called lipoprotein.

There are four types of lipoproteins namely –

1.   Chylomicrons which are rich in triglycerides

  2.   High density lipoproteins (HDL)

  3.   Low density lipoproteins (LDL)

  4.   Very low density lipoproteins (VLDL)

High levels of chylomicrons and LDL are associated with a higher risk of heart attacks. High levels of HDL protect against heart diseases.

2.  What are the dietary sources of fat ?

Fat is derived from either animal or plant food. Animal products rich in fat are milk, cream, butter, ghee, cheese, animal fat etc. Plant products which are rich in fat are various oil seeds and nuts, e.g. soyabean oil, til (Sesame) oil, groundnut oil, coconut oil etc. Cereals, pulses, fruits and vegetables hardly contain any fat.

   The fat content of common food items is given ahead.

Food item	Fat content (%)	Food item	Fat content (%)
Ghee and oil	100	Soyabean	20
Almonds	59	Mutton	13
Cashewnuts	46	Milk of a buffalo	7
Groundnuts	40	Milk of a cow	3 .5
Cheese	25

3.  What are essential fatty acids ?

Man cannot synthesise some polyunsaturated fatty acids like linoleic, linolenic and arachidonic acid from other fatty acids in the body. Hence, one’s diet should contain these fatty acids. These are called essential fatty acids. These unsaturated fatty acids are necessary for growth, integrity of the skin and hair, reproduction and control of other fats in the body. The linoleic acid content of certain fats and oils is given in the table ahead.

Oil or fat	Linoleic acid (%)	Oil or fat	Linoleic acid (%)
Sunflower oil	75	Mustard oil	20
Corn oil	51	Vanaspati	6
Cotton seed oil	50	Coconut oil	3
Til (Sesame) oil	40	Ghee	2
Groundnut oil	28

4.  What are the symptoms of fat deficiency ?

Weakness, malnutrition, loss of weight and craving for fatty food items are the manifestations of fat deficiency. Deficiency of essential fatty acids in the diet affects growth and gives rise to dryness and thickening of the skin.

5.  What are the symptoms of excessive intake of fat ?

Consuming a large quantity of fat in the diet gives rise to symptoms of indigestion such as loss of appetite, vomiting, heaviness in the stomach and greasy and sticky stools.

If digested, the excess fat is stored in the body in the form of body fat. Excessive fat intake over a long period of time leads to overweight and obesity. Increase in the fat (Cholesterol and triglycerides) levels in the blood over a long period leads to its deposition on the internal lining of the blood vessels. The internal lining of the arteries becomes rough and blood gets clotted when it comes into contact with this rough surface. If a blood clot forms in the coronary artery which supplies blood to the heart muscle, the person suffers from a heart attack. If the blood clots in an artery supplying blood to the brain, the person suffers from a paralytic stroke. Egg yolk, brain, kidney and liver of animals, lobsters and oysters are rich sources of cholesterol and should be avoided or taken in a restricted quantity by old people and sedentary workers.

If 40% of energy or more is derived from fats, it increases the chances of a heart attack in sedentary workers and old people. In such people, fat should provide only 15% of the daily requirement of calories in the diet. Instead of receiving this energy from animal fat and ghee, it should be taken in the form of vegetable oils like groundnut oil, til oil, sunflower oil etc. which contain high proportion of unsaturated fatty acids that do not increase blood cholesterol.

If a starving person or a person suffering from diabetes or severe infection consumes a large quantity of fat, he is unable to digest and utilise it. The incompletely digested fat known as ketone bodies (Acetone, acetoacetic acid and betahydroxy butyric acid) accumulates in the body causing acidosis and gives rise to heavy breathing and unconsciousness due to its toxic effects.