Newborn Nutrition 101

You’ve probably been so focused on making sure you got enough nutrients while pregnant, and now your baby is here! Feeling unprepared and overwhelmed? You’re not alone!

Newborn Nutrition 101

Written by: Jessica Diamond, MPH, RDN

You’ve probably been so focused on making sure you got enough nutrients while pregnant, and now your baby is here! Feeling unprepared and overwhelmed? You’re not alone! We focus so much on our nutrition for pregnancy and birth that, once the baby arrives, we often don’t know where to start! We’re here to break it down for you, whether you are formula-feeding or breastfeeding. To start, here are a few tips for feeding your newborn in those first few days and weeks:

  1. Your baby should be eating 8-12 times a day. That means every 2-3 hours. Holy cow is right! This will vary for breast-fed versus formula-fed babies, but the main thing to remember is that you will be feeding around the clock. When your baby is born, their stomach is the size of a pea, and it grows as they grow. So, in the beginning, they need small but frequent feedings. And timing is important here: every 2-3 hours means every 2-3 hours from the start of the feeding. For example, if you feed at 10am and the feeding ends at 10:45am, then your next feeding should be scheduled between 12-1pm. It should feel like you are feeding all the time! This is what your baby needs in their early days.
  2. Starting at birth, your baby should have about one wet diaper per day of life for the first week. This means 3 wet diapers on Day 3 of life. After the first week, your baby should have 6+ wet diapers per day. Counting the number of pee diapers will help you keep track of their hydration levels and adjust breastmilk/formula as needed. And what about poop? It’s good to keep track of it, but the number of pee diapers is what will help you gauge whether your baby is getting enough formula or breastmilk.

    To make life easier, we recommend keeping a baby journal that tracks feedings, pee diapers, poop diapers, and sleep. This will help you keep your bearings in those early blurry-eyed and sleep-deprived days and weeks. Check out our favorite baby tracking apps and journals here. It’s nice to have a paper journal so that any parent or caregiver can update the journal and keep the whole family in the loop. Plus, it’s a fun keepsake!
  3. Your baby will probably need to be woken up for feeding during the early days and weeks of life. This is normal. Once your baby’s stomach grows bigger than a marble and can hold more breastmilk and/or formula, you can decrease the overnight wake-ups.
  4. Your baby should regain their birth weight by 2 weeks old. It is normal (and expected) that your baby will lose weight in those early weeks, but ideally, your baby should be back to their birth weight by the end of the second week.

    Newborns lose weight for two reasons. First, they are no longer attached to the umbilical cord and therefore getting fed 24/7. Now that they are earth-side, they will need to learn how to feed from the bottle or breast, all while expending a lot more energy living. (Think of all the breathing and movement they are now doing on their own!) Second, newborns are filled with fluid from living (and swimming) in your belly before delivery. In those early days, babies will get rid of all that fluid, and this will make them lose weight.

    And just a note: research has shown that babies delivered by C-section tend to lose more weight after birth from fluid loss because they lose less fluid during the birthing process. So, expect a greater dip in weight if your baby was delivered by C-section.
  5. Your baby may need Vitamin D supplements if they are breastfed. Liquid Vitamin D can be added to a bottle or to the breast if breastfeeding. (If you are formula-feeding, you don’t need to worry about Vitamin D since formula already has plenty of it.) Here are our favorite brands of Vitamin D for babies. Ask your pediatrician about Vitamin D supplementation at the first visit after your baby is born.

For more on all the basics you need to know about feeding your growing baby, check out these other resources:

And make sure to take our Feeding Your Baby Solids course once your baby is 3 months or older. Trust us, it will be the best money and money spent.