Five Compartment Model

The five-compartment model is a method used to assess body composition by dividing the body into five distinct compartments:

1. Fat mass (FM) - the total mass of adipose tissue in the body, which is responsible for energy storage and insulation. The percentage of fat mass varies greatly among individuals and depends on factors such as age, sex, and overall health. On average, fat mass can range from 10-25% of body weight in males and 20-35% in females.

2. Fat-free mass (FFM) - the total mass of all tissues in the body excluding fat. Fat-free mass can be further divided into the remaining compartments:

3. Total body water (TBW) - the total amount of water contained within the body. Water is a major component of cells, blood, and extracellular fluids. Total body water typically accounts for around 50-60% of an adult's body weight.

4. Protein mass (PM) - the total mass of proteins in the body, including structural proteins like collagen, enzymes, and transport proteins. Protein mass accounts for approximately 18-20% of body weight.

5. Mineral mass (MM) - the total mass of minerals in the body, mainly found in bones and teeth. Mineral mass accounts for about 4-5% of body weight.

It's important to note that these percentages are rough estimates and can vary depending on factors such as age, sex, overall health, and body composition. The five-compartment model provides a more detailed and accurate assessment of body composition compared to simpler models like the two-compartment model (dividing the body into fat mass and fat-free mass) or the three-compartment model (dividing the body into fat mass, lean body mass, and bone mineral content).