Body composition refers to the proportion of fat and lean mass (muscles, bones, organs) in the body. It is crucial for health assessment because it provides insight into an individual's overall fitness and health risks. High body fat percentages are associated with greater risks of diseases such as diabetes, cardiovascular problems, and certain cancers. Understanding body composition rather than just weight gives a more accurate picture of health, guiding interventions and lifestyle changes. Regular assessments help track changes over time and measure progress toward fitness goals.