The caloric requirements of the human fetus have been calculated from the reported values of the fetal oxygen consumption and the composition of the new tissue deposited, both expressed as their caloric equivalents. It is estimated that the deposition of fat represents over half the caloric accretion from the 27th week of gestation until term, and ∼90% of the caloric accretion at term. The total caloric requirement of the human fetus at term is estimated at ∼90–100 kcal/kg/day.