Yes! Breastfeeding will help you lose weight and tone up your insides because of the energy drain of producing milk. You have stored added fat during pregnancy in preparation for breast-feeding. Studies show that if the mother nurses, all this stored fat is “burned” by the end of the nursing period (asuming you don’t “pig out” on a ton of excess calories). In contrast, the fat remains if the mother doesn’t breast-feed, and she must cut calories or increase exercise to get the same results.