The preferred source of energy for the body is carbohydrates. However, the storage of carbohydrates in the body (glycogen) is depleted within a few hours. When the body storage of glycogen is depleted...The preferred source of energy for the body is carbohydrates. However, the storage of carbohydrates in the body (glycogen) is depleted within a few hours. When the body storage of glycogen is depleted, the production of certain hormones stimulates the hydrolysis of lipids. Mobilized fatty acids in the blood are transported to the required tissue forming a lipoprotein complex with serum albumin protein. Serum albumin is produced by the liver and is the most abundant blood protein in mammals.