Final answer:
During lactation, the recommended dietary allowance (RDA) of Energy (kcal) is higher than during pregnancy.
Step-by-step explanation:
The nutrient whose recommended dietary allowance (RDA) is higher during lactation than during pregnancy is Energy (kcal). During lactation, a mother needs to consume extra energy to meet the energy cost of milk production. The efficiency of milk production requires the mother to expend more energy than the energy value of the milk produced.