Representative multicomponent models at the 5 body composition levels
| Level | Body composition model | Number of components |
|---|---|---|
| Atomic | BM=H+O+N+C+Na+K+Cl+P+Ca+Mg+S | 11 |
| Molecular | BM=FM+TBW+TBPro+Mo+Ms+CHO | 6 |
| BM=FM+TBW+TBPro+M | 4 | |
| BM=FM+TBW+non-fat solids | 3 | |
| BM=FM+Mo+residual | 3 | |
| BM=FM+FFM | 2 | |
| Cellular | BM=cells+ECF+ECS | 3 |
| BM=FM+BCM+ECF+ECS | 4 | |
| Tissue-organ | BW=AT+SM+bone+visceral organs+other tissues | 5 |
| Whole body | BW=head+trunk+appendages | 3 |
AT, adipose tissue; BCM, body cell mass; BM, body mass; CHO, carbohydrates; ECF, extracellular fluid; ECS, extracellular solids; FFM, fat-free mass; FM, fat mass; M, mineral; Mo, bone mineral; Ms, soft-tissue mineral; SM, skeletal muscle; TBPro, total body protein; TBW, total body water.