Why Fats are essential for meeting nutritional need of essential?

Fats are essential for meeting nutritional needs of essential, fatty acids like linoleic acid (n-6) and alpha linolenic acid (n-3). These essential fatty acids are needed for the synthesis of important eicosanoids. Saturated fatty acids, monounsaturated fatty acids and cholesterol can be synthesized in the body, hence the diet only adds-on to their total amount available in the body. Excessive intake of SFA and cholesterol in diets can therefore be harmful. Excess n-6 impairs desaturation and elongation of linolenic acid to EPA and DHA.