Abstract
The human body is a complex system that requires energy to function properly. The most common sources of energy for the human body and that are called nutrients come from plant and animal origin. The nutrients include carbohydrates, proteins, and lipids. This chapter focuses on the three major groups of nutrients that the human body uses to obtain energy in order to perform its functions.
Keywords: Amino acid, carbohydrates, disaccharide, fats, glicerophospholipids, glucose, glycerides, histidine, isoleucine, lactose, leucine, lipids, lysine, maltose, methionine, oils, phenylalanine, polysaccharide, proteins, sucrose, threonine, tryptophan, valine.