Explain the Metabolic Aberrations of Underweight?

When energy intake falls below the minimal requirements, the body responds with an orderly physiologic adaptation involving the hormones of energy metabolism. This causes mobilization of free fatty acids from adipose tissues and of amino acids from muscle to provide energy. Protein synthesis is cut down because proteins are burnt up for providing energy to the body. The metabolic rate of the body is reduced and lean body mass and adipose tissue contract resulting in weight loss. Under nutrition is generally accompanied by protein deficiency in the body. Fortunately, the condition is reversible with proper nutritional support.