Body Mass

• Body mass is significantly decreased in a heterogeneous way.

Fat Mass

• Fat stores can decrease to a low as 5% of the total body weight and be macroscopically undetectable.  The remaining fat is usually stored in the liver.

Total Body Water

• The proportion of water content in the body increases with the increased seriousness of protein-energy malnutrition and is associated with the loss of fat mass, which is poor in water.  The proportion of extracellular water also increases, often resulting in edema. 

Protein Mass

• Mainly represented by muscle and some organs (eg heart), protein mass can decrease up to 30% in the most serious forms.  The muscle fibers are thin with loss of striation.  Muscle cells are atrophic, and muscle tissue is infiltrated with fat and fibrous tissue. 

Other Organ Mass

• The brain, skeleton, and kidney are preserved, whereas the liver, heart, pancreas, and digestive tract are first affected.