My 12-month-old daughter has been continually slipping in the growth charts (from the 25th percentile down to the 5th). She is a very active child and is small-boned. In addition to her three homemade meals, she gets two snacks, water to drink, and I breastfeed her 5-6 times per day. My pediatrician said that my breastmilk is basically water at this point and that I shouldn't be filling my daughter up with it? Is this correct?
I hope this is not too harsh to say but you asked for "my opinion." My opinion is that a pediatrician should have at least some basic understanding of nutrition, especially if he/she is going to try giving nutritional advice. Your pediatrician may be good for emergency care but for more common health questions, I suggest you find someone who is educated with more than just baby food industry propaganda.
If your doctor is concerned about too much water, then you should stop the water, but I wouldn't do that. Solid foods need water with them. I wonder what exactly your doctor wants to see in your daughter's food that she can't attain from breastmilk? With its protein being more completely absorbable than proteins from other foods, breastmilk provides the exact balance of calories from proteins, carbohydrates and fats that are recommended for young children. It's a little higher in fat than a commonly recommended adult diet, though not to any unhealthy degree, because it's all the right kinds of fats. Balanced nutrition? Breastmilk provides all the nutrients needed in a healthy diet while other foods need to be combined with each other in order to obtain complete coverage of nutrients. Worried about her health? Of course breastmilk still provides special, valuable immune assistance. Nothing else will ever be able to provide this. Once it's gone, it's gone, though the longer a child breastfeeds, the longer her immune system is boosted for; lasting for a greater extended period beyond weaning the more weaning is delayed. Concerned about mental development? Studies show that the longer a child receives breastmilk the greater their mental and motor abilities.
I'm sure you aren't restricting the amount of food your daughter is allowed to eat. She knows exactly how much she needs. There's no reason to restrict her mommy milk either. Your daughter's activity has led her to lose her baby fat and now, being small boned, she will remain in lower portions of the weight charts as long as she does not develop excessive fat. I'm also guessing that at least one of her parents is not very tall. There are plenty of studies showing that rapid weight gain in these earliest months leads to increased risks for heart disease, diabetes, obesity and cancer further down the road. There are no negative long term findings for slower growths. As long as your child is happy, active and alert, and achieving developmental milestones, there's nothing to worry about. Keep up the good work mom.