During pregnancy and during breastfeeding a woman is advised to take more calories than she was taking before pregnancy to fulfill the demand of energy of the baby and her body.
A breastfeeding woman whose baby is less than 6 months should take 450-500 calories extra than the calories which was required to maintain the body weight of the woman before the pregnancy.
In a study, it is found that healthy breastfeeding women consume between 1800-2200 calories per day.
You want to eat well (dark green vegetables, fruits, and various meats.) along side with a consistent fitness schedule that consists of a balanced amount of cardio and weight lifting.