According to the life course heath model, health differences in emerging adulthood are an outcome of: exposure to:

Health differences in emerging adulthood are an outcome of exposure to: risk and protective factors during prior developmental stages, based from the life course heath model.

These differences may be caused by factors such as poverty, illegal drugs, child abuse, etc. Such factors, such as poverty, affects the health difference in emerging adulthood in a way that a child in a rich family may have sufficient food while another one may be lacking in nutrition due to poverty.