Features

Your weight is a mixture of lean mass, fat mass, and water mass. Weight loss is a result of some combination of water, fat and/or lean muscle mass loss.

Percentages

Your body needs a certain amount of fat to maintain health. The minimum body fat percentage for women is 15 percent; for men it's 5 percent. Your body also needs an adequate amount of water to function properly. Approximately 50 percent of a woman's body weight is water, 60 percent for a man.

Methods of Measuring Body Fat

In order of least to most open to error, the three top ways to directly measure body fat percentage is through hydrostatic weighing (which can be expensive), the skinfold method, or bioelectrical impedance analysis, which can be done using a body fat scale.

Relationships

Most of the water in your body is in your muscle tissue. Water makes up 75 percent of your muscle mass, but only 25 percent of your fat mass.

Effects

A drastic loss of muscle mass can lead to moderate or severe dehydration. Starvation dieting promotes the catabolism of muscle protein and can lead to drastic muscle, and thus, water loss.

Tips

Use the Total Body Water Calculator to help estimate your water weight percentage.

Source:

UNM: Body Composition

Alabama A&M: Hydration

Dehydration

Resource:

Total Body Water Calculator

Skinfold Test Procedure