The rumour that you have to eat for two during pregnancy persists. The fact is: A pregnant woman's calorie needs only increase by around 200 to 300 kilocalories per day. So it is not necessary to eat for two. Instead, future moms should eat twice as consciously. Only during the breastfeeding phase does the requirement increase by around 500 kilocalories. Mothers pass on the additional power to their babies, which is why they lose weight naturally and gently during this phase: around a kilogram every month.