Question

1. There are a number of techniques available to measure body composition.
   1. Describe the 2, 3 and 4 compartment models that are available for body fat estimation.
   2. List which techniques would be considered gold standards and which predictive?
   3. If you were going to perform a research study (and money was not an issue) which body composition technique would you use and why?
   4. If you needed to estimate body composition in a club setting which technique would you use and why?
   5. Explain which techniques can be used and which techniques should not be used to estimate change in body composition before and after an intervention?

Answer 1

a.

• Two compartment model (2C) - Consists of body compartments of fat, fat mass, fat-free mass. It is measured based on bone density, TBK, and TBW. The storage of fat-free mass tissue remains constant.
• Three compartment model (3C) - It expands the components of the 2C model. Here Fat-free mass is further divided into fat mass, total body water, and fat-free dry mass. Protein and bone mineral content are included in this.
• Four compartment model (4C) - It divides body components into fat mass, protein, water, and mineral. BMC measured the mineral component and neuron activation measured the protein mass. It also divides the body in another way as body cell mass, extracellular fluid, and extracellular solids.

b. DEXA is considered as gold standards technique. It measures the total bone mineral in the body. It is assumed that it differentiates the tissue composition, fat, and bone. It is widely used in nutritional studies. It is based on 4C models.

c. Direct methods are used in research studies such as DEXA, estimation of total body water, and total body counting and neuron activation.

d. Near Infrared Interactance (NIR) is used to measure body composition based on the light reflection. It is inexpensive and widely used in health clubs, fitness centers, weight loss programs.

e. Dual-energy X-ray absorptiometry(DEXA), Bioelectrical impedance analysis(BIS), are the best suitable technique to estimate the change in components before and after an intervention. These provide accurate measurements comparing to other techniques. The 2C model or 3C model cannot be used because it does not show any changes due to loss of energy.