Lean body mass (LBM) refers to the mass of the body that does not include fat. LBM is primarily composed of muscle, bone, and water, and it accounts for most of the body’s active metabolic tissues. For instance, a person weighing 200 pounds with 15% body fat would have 170 pounds (200 * 0.85) of lean body mass.
Determining LBM is crucial for various health-related reasons. It helps individuals understand their body composition, track fitness progress, and adjust nutrition and exercise plans. In the field of medical research, the concept of LBM has played a significant role historically. For example, the invention of the body composition analyzer in the 1960s enabled precise measurement of LBM, contributing to advancements in understanding obesity and malnutrition.