Fatty Acids are the basic structural units of Lipids. Lipid is the general term which refers to dietary fat. The body can synthesize many fatty acids. However, those which it cannot manufacture in adequate amounts must be obtained from the diet, and are termed Essential Fatty Acids (EFAs). Fatty acids can be saturated, monounsaturated or polyunsaturated depending on the degree to which the basic carbon chain of the molecule is filled with hydrogen.