Protein-energy malnutrition is a form of undernutrition caused by an extremely deficient intake of calories, protein, or both. Two examples of this type of malnutrition are kwashiokor and marasmus. Protein-energy malnutrition is more often caused by decreased absorption or abnormal metabolism. It is defined as a range of pathological conditions arising from coincident lack of protein and/or energy in varying proportions. The condition vary in forms ranging from mild through moderate to severe degrees.