Your body goes through massive physical and hormonal changes right after delivery and then must start producing milk for your baby. You don't need to increase your calorie intake. Breast-feeding increases your calories need by calories per day, about the same as pregnancy, according to the Ohio State University Extension. Foods high in protein, whole grains, iron, calcium and omega-3 fatty acids should all be part of your postpartum diet as a nursing mom. Breast-feeding moms need slightly more protein than non-nursing women, around 71 grams per day, according to the Ohio State University extension.