Research & Science
June 20, 2022
· Written By
Ted Handler

Your Top Child Nutrition and Behavior Questions, Answered

At Oath, we tackle the topic of nutrition in combination with behavior and emotion. That’s why we brought a pediatrician, pediatric nurse (and grandmother), and marriage & family therapist together to answer the top questions in our community. Read their responses below.



Iron 🏋️‍♂️

“Why is iron important?”

Dr. Ted: I am an iron evangelist. It is crucial for transporting oxygen to our brain and vital organs as we grow, and is connected to brain development and behavior. There are studies that show lack of iron can be linked to restless legs, sleep, emotional regulation and ADHD. Iron is one of those nutrients worth paying attention to for your child.

Nurse Judy: An example of iron being the culprit behind sleep challenges came up in a call I received from a family of vegetarians. Their two-year-old was having trouble sleeping so I suggested they offer him some meat. Turns out 1) he loved it 2) he started sleeping like a champion. He was missing nutrients & it was really impacting his health.

Dr. Ted: There are two kinds of iron: heme iron (ex. meat) and non-heme iron (ex. beans, lentils). Our bodies are well-suited to soak up & utilize heme iron, but struggle to do the same with non-heme iron. In order to help our bodies utilize the iron in veggie sources, pair them with vitamin C. So for example, spritz some broccoli with lemon. This improves iron intake by 10x!

“Iron came back in the low range for my child after a recent doctor’s visit. Should I be worried?”

Brittany, Therapist: I often see in my line of work where parents can give too much power to charts & percentiles. They can allow where their child is on these charts to affect how they see their kids. I recommend cognitively reframing: “I’m so thankful we have the diagnostic tools to see how my son/daughter is doing.” But try not to allow the anxiety to creep in around exactly where they fall. Stress hormones released when feeling concerned can start to impact our own health.

Dr. Ted: The advancement of technology has created a narrative that there are numbers hiding in our body that might mean something bad if we don’t catch it. In pediatrics, there are very few things that hide in the darkness.

Nurse Judy: Are they sleeping well? Are they bright-eyed and bushy-tailed? Do they look healthy? If they are not having any issues that you can see, then I would simply focus on having an iron-rich diet with vitamin C and not worrying about the numbers. If you see things like dark circles under the eyes, or your child is restless, then talk to your doctor about getting a supplement to get that number up.

“Do you suggest iron supplementation? Why do iron supplements cause constipation?”

Nurse Judy:  If your doctor has suggested supplementing iron:

  1. Ask about the recommended dose first and pay attention to the dose in all of the various forms available (e.g gummies, drops).
  2. If you choose a yummy form that your child likes, consider storing it out of reach and only serving their recommended dose. If your child takes too much iron because they love munching on the vitamins, it can cause a stomach ache/constipation.

Brands that I recommend:

Dr. Ted: If you do start supplementing, you might retest to keep an eye on the impact of that supplement on your child’s health. Iron lives on a time scale of 3 months. If you do want to re-test, test no sooner than 3 months after starting the process to get an accurate result on how those levels are progressing.

Regarding constipation, large heavy elements like iron can slow down the gut. Without Vitamin C helping the body absorb the molecule, it can just sit there and is heavy in the body which can be hard for the intestine to move. So, pair iron with Vitamin C, water and fiber to combat constipation.

Sugar 🍬

“How impactful is sugar on a child's development?”

“I fight about not wanting goldfish, cereal, processed food in my kids' bodies. Now with 3 kids I've relaxed a lot. Should I hold my ground? Is it ok to cave?”

Brittany, Therapist: As a mother of two, I can attest my balance looks different with two kids than it did with one. I love that you are questioning how strict or rigid you should be. People feel so much guilt around what they feed their kids. Lay the foundation and then have faith.

Nurse Judy: There’s going to be times in their lives when they are going to get the goldfish. That is a fact of life, and goldfish happens. But, we want to give the attention to the foods we want to see more of. So when they are eating healthy food, we want to say things like “I’m really happy to see you are eating this healthy food, it’s great for your body! This will help you grow.”

Dr. Ted: To get concrete about volumes: roughly 50% of the volume of food on a plate should be fruits and vegetables, then 25% protein, and 25% carbs. This is rarely achieved, but it’s a good goal.



In general, it is nice if we can avoid processed carbs, which have inflammatory qualities. However, there is just as much research showing that good microbiomes, fed by healthy fruits and vegetables, can counterbalance some of the inflammation caused by those processed carbs. So, if you’re getting in a good amount of fruits and vegetables at mealtime, you can rest assured you’re not going to be slipping into any danger areas highlighted in headlines.

“What are your recommendations for managing our children’s desire to consume all the sweets during the holidays?”

“One a day? Splurge on a special day? Let them eat it until they get sick?”

Brittany, Therapist: It's my preference to let them have a sweet once per day during the holidays. It's important to match the behavior with a brief verbal "This is special behavior because it is the holiday and isn't the new norm." Listen to your parenting intuition. Be mindful of the emotional nourishment that you're also giving them. The feeling around food, sweets, the holiday is just as important as the physical nourishment.

Nurse Judy: It’s important to have a balance at home so that your kids don’t feel that they need to sneak anything. For example, my kids got to pick and have a sweet cereal on weekends. When friends would come over that had no access to sugar, they were so excited that was all they wanted to eat…making it scarce adds a value that we don’t necessarily want. As long as they can have some amount of sweets, hopefully they will be less likely to binge.

Dr. Ted: The research suggests that it really might be harmful to have MASSIVE sugar infusions. I fall into the small treats camp, and spread out over time, and not as a reward for finishing vegetables.

Picky Eaters 🤢

“How do I consistently feed veggies when he seems to fall in and out of love with different veggies every week?

Brittany, Therapist: This feels similar to emotions. I’m sitting in a different emotion right now than how I was feeling 2 hours ago. It’s okay for preferences to wax and wane.

Nurse Judy: It’s all about valuable attention. If they are eating string beans all week, then don’t give too much attention to that. But if you’re trying to encourage more broccoli, then when he does do the broccoli, throw a little attention party. “Woah, you’re eating broccoli, look how strong you are!” Feel their muscles, and show energy and excitement around trying something new. But as long as he is eating and trying things, that is great!

Dr. Ted: Remember this happens to us as adults, too. You might not be in the mood for pizza when someone puts pizza in front of you. It’s not because you don’t like pizza on a different day, you’re just not in the mood for it. There’s also some kids who will reject a vegetable that they previously liked, and they will continue to reject it consistently. The child nervous system is growing in this absolutely fantastic way and it is very strong, powerful and electric. Sometimes senses or tastes can come up that kids develop a strong aversion towards. In order to diminish the aversion, you can repeatedly expose the child to the vegetable. That repeated exposure does something called potentiation which allows the nervous system to connect the scent to something more familiar, and less scary and less foreign. So if they reject something on one day, and you do it again the second, third, fourth, fifth…it’s going to get boring and you’re going to have string beans for 10 days, but on the 12th day, they will not reject it.

“How do I get my kids to eat the healthy meals I cook?”

“I like cooking homemade healthy meals and my children whine and won’t eat them… what are good options in that scenario? I want to force them to eat it because I took time to cook it, but that probably causes food or control issues.”
“In the last few weeks, several times per week, when I offer a healthy dinner to my children, my six-year-old will refuse to eat it. Do I tell her she gets no dinner, or is it appropriate to allow them to opt out and eat oatmeal or cereal?”

Brittany, Therapist: This just happened to me! I like that you have the awareness of a need to create control. “I want to control this situation, I made this meal and I want you to eat it.” Compromise so you don’t become a short order cook: eat enough until they feel satisfied. It’s okay to feel a little hurt by this, don’t let it bruise you. It’s okay to say “that didn’t feel good for mommy to hear that. I put a lot of effort into this meal and I was excited about it.” Kids are emotional. Before they can intellectually navigate this world, they can emotionally feel their way through it. So, I encourage you to be honest with your kids and share how that made you feel.

Nurse Judy: Use the “as soon as” strategy. “As soon as you try one bite, then you can have x.” I don’t mind giving them a fallback. It’s easy and not a battle, they’re not getting attention. But, you can give attention to trying something new. “I’m so excited you tried what I made!” or “I’m so excited you sat with the family while we tried this meal!

Dr. Ted: Yes to all of the above. My favorite is to say “Ok, you don’t want this dinner. It can go back in the fridge and if you want it later, you can eat it when you’re hungry..” But the strategy of “have one bite, then you can have x” also works. It depends on you and what feels most comfortable in maintaining a relationship with your child.

“What do I do if my kids refuse to eat fruits and vegetables?”

“I have an 8-year-old that has only been eating white foods for four years with no meat and very little fruits and vegetables. Every meal is an exhausting battle. I lay everything out to offer her heathy suggestions with no avail. I have been waiting for her to outgrow it but it’s only getting worse.”
“My 2-year-old will almost never eat veggies. I have done repeated exposure for lots of different veggies and I have about a 5% success rate. I won’t give up and will continue to be creative but it is frustrating, exhausting, and makes me feel like I am setting a bad long term precedent.”

Brittany, Therapist: This is a frustrating situation for anyone in your shoes. Try a strategy to make mealtime more fun and help your child feel ownership in the creation of the meal.

Nurse Judy: There are a few things you can try:

  • Play a game that teaches kids about fruits and vegetables and gives them an action plan to try new foods.
  • Nutrition Recognition Bingo
  • Healthy Helpings MyPlate Game
  • Children’s Book & Placemat Game
  • Tell stories about another child, with a similar name, who only eats white food and one day they didn’t feel well because their body needed some protein. In the story, you can include that one day they tried a new food (or made a smoothie) and that helped them. Then ask at the end if you child would be willing to try that same idea.
  • Try the one-pea-at-a-time method. Give them a tiny amount (even one pea) and let them have success. “As soon as you have your one pea, then you can have your white food.”  
  • Hide nutrition in smoothies, pancakes, waffles.

Dr. Ted: The backseat anxiety monster tells us a parents that our child is malnourished if they are not eating their fruits and vegetables. It’s important to know the body knows exactly what to do with vitamins when it gets them. So even the 5% of vegetables and fruits they are getting will be soaked up in full by the body. And that’s a win!

“Is a multivitamin my only option if I have a picky eater?”

Nurse Judy: Multivitamins are an option, but they’re not the only one. Try a little gummy they will take without a battle in order to get the nutrition in.

Dr. Ted: It can be excruciating to wean a child from white foods but it is possible. The body will regulate. That involves decreasing the volume of food your child gets and only offering the fruits and vegetables. That might mean that for a long time they will throw tantrums. But those tantrums will decrease quickly as they start to self-regulate. What that means is that it will feel as though you are starving your child. They might skip a lot of a dinner. They might skip breakfast. In the hospital, a child can go fully without a single piece of food for 7 entire days.  So long as they are hydrated and with essential electrolytes, we will not put them on IV nutrition until after the 7th day.

Nurse Judy: I like to offer options. “Today we don’t have pasta. But we do have x and y.” If they fuss about the choices, then they might be a little hungry, but eventually they will come in and take those choices.

Brittany Williams: There’s a power struggle here and it is hard to get the power back. No child is doing this on purpose, but they do what works. If the child kicks and screams and finally get their favorite food, then they will continue to do that. If mom and dad are modeling solidarity, you will see a shift happen a bit faster.

Other Topics 📚

“Can we be giving too much solids to baby?”

“We’ve been offering a pouch that is 3.5 oz. Should we let them eat the whole pouch as a meal? Or should we stop giving at a certain amount, since milk is the primary nutrition still for our 6-month-old?”

Brittany, Therapist: This is a great question to demonstrate what it looks like when we get flooded (spiral) with a lot of thoughts on one topic, and that creates an excess of energy or what we often refer to as anxiety. When you see this, take a deep breath and try to zoom out.  What came before the influx of thoughts?  Once you can identify that, you can “slow the leak” and move forward from an emotionally regulated stance. For this question, it helps to focus on that first question, rather than showering ourselves in “shoulds”.

Nurse Judy: Milk is a primary nutrition source through 6 months, afterwards solids become equally important. Let them guide you. Your job is to offer, their job is to let you know what and how much. We can usually trust them unless they are the rare ones that don’t have an off switch. In terms of knowing if they have the right balance, I look at pee and poop. If those are both normal and baby seems content after a meal, then it seems good.

Dr. Ted: The only thing I’ll add is to be a label reader. The pouches can be a little problematic with the way they prioritize sugar. Apple or grape should be far down the line if present in the ingredient list, not first.

“How do you manage kids who don’t drink water?”

Brittany, Therapist: It's okay to reward good behavior. If the child is old enough to respond to a reward system for drinking water that's okay. Equally as important is to model, model, model behavior. Show your child your water bottle. They could get a "special" water bottle for drinking water. Some kids prefer filtered water, others bottled. Some room temperature, some ice cold. Don't forget to be curious. One way to avoid letting it become a power struggle is to be conscious of your in-the-moment response. Use the poker face and be consistent/firm in offering water (with a tiny splash of juice) 😉

Nurse Judy: It’s OK to add a tiny splash of juice. Bright colors often have lots of good vitamins.

“What are the most important foods to build immunity?”

Dr. Ted: I truly wish that I had great data to share about foods that boost the immune system! To date, scientists have failed to produce any reliable good studies demonstrating that anything in the diet can decrease the rate of colds or infections. And I promise it’s not for lack of trying… there have been numerous massive government-funded and private studies that have examined all of the major vitamins and nutrients, and we still haven’t found good randomized controlled data to show benefit in children that already have a well-balanced diet. But, that’s not true for children in resource-limited areas! Being deficient in vitamin A, vitamin D, zinc and others have all been shown to be associated with a weakened immune system, but that doesn’t mean that adding extra to a healthy diet will give you a better immune system.

Ted Handler

Founding Pediatrician at Oath Care and general pediatrician in the San Francisco Bay Area.