Early childhood nutritional factors can play a crucial role in the development of body composition in later phases of life. A systematic literature review was conducted to identify studies on the association between early nutritional determinants and fat-free mass in adulthood. The PubMed and Virtual Health Library electronic databases were used. Nine articles were included after a peer review of the 576 references initially found, published from 2003 to 2009, with healthy subjects and longitudinal analysis. Birth weight and birth length and variations across childhood were strong predictors of fat-free mass at later ages. The studies showed that higher birth weight and greater weight gain in early childhood were associated with greater fat-free mass in adulthood. However, the available data are limited and inconclusive in relation to eating in early childhood as a predictor of fat-free mass at later ages.