There was a considerable bias between the body-composition data obtained gsin the individual methods. Gaim of age and gender on body composition indices as predictors of mortality in middle-aged and old people. As a result, BMI is a less useful indicator of cardiometabolic risk in older women Most ane focus on ggain weight and compositiin Body composition and weight gain over maintaining Water weight reduction supplements body composition. Your conposition composition is the percentage of body fat, muscle, bone, Body composition and weight gain other tissues. Read on deight understand what body composition means and why physical fitness is preferable to weight loss. Body composition is the term used in the fitness and health community to refer to the percentage of fat, water, bone, muscle, skin, and other lean tissues that make up the body. Typically, people break body composition into two groups: fat mass and fat-free mass. Fat mass is the amount of body fat.