Breastfeeding weight loss, although it does have many benefits, does not happen automatically. Most women think that just because their bodies are burning an extra 500 or so calories by producing milk for baby that they can eat what they like. Not true according to many studies. A more direct link between weight gained during pregnancy and how fast weight comes off postpartum, can be argued. Some women even gain weight while nursing.
Good food choices and a healthy exercise plan are still needed to safely lose weight while breastfeeding. Something more important to consider than losing weight quickly, is the nourishment of yourself and your baby. If you aren't eating enough, it is probable that you are not getting the nutrients needed for a healthy milk supply. It's best to not even attempt to lose weight for six weeks after delivery.
As a new mom, exercise will be hard to come by. You will have enough on your plate taking care of baby. Because you won't be able to burn more calories as somebody on a regular exercise routine, you need to concentrate on your diet. Most women need somewhere in the neighborhood of 2000 calories a day to maintain a healthy diet that will supply milk for baby and leave enough nutrients for mom. Don't waste those vital calories with junky foods that offer no nutritional benefits.
An important balance of proteins, fats, and different vitamins are essential. For instance: lets say you drink a can of soda which contains about 170 calories. It contains no vitamins, no fats and no protein. You have just wasted nearly 200 calories in your 2000 calorie per day plan and didn't receive any beneficial nutrients for your body.
Go here to learn more about many good books and programs on the market to help balance your diet and help you achieve breastfeeding weight loss.