To determine the energy savings caused by sucrose taste, we measured heat loss through direct calorimetry for 23 premature and normal term infants who were studied a total of 31 times. Following stabilization in the calorimeter, crying was induced by applying 1 ml cold water to the infant's foot. After 4 min, 0.1 or 0.2 ml sucrose were delivered intraorally through a remote syringe to arrest crying. Crying was accompanied by a 13.2% increase in metabolic rate that was quickly and completely reversed during crying cessation caused by sucrose taste. Heat loss was inversely and linearly related to infant body weight. The implications of these findings for minimizing crying and energy expenditure in normal newborns and especially in ill or small newborns are discussed.