Is your child underweight? If your child is underweight, your doctor would have told you, right?
Maybe not.
In my pediatric nutrition practice, I am often the first person to capture underweight status or even growth failure in a toddler, child or teen who has seen multiple providers, from the pediatrician, to gastroenterologist, to allergist, to functional medicine experts, and so on. Being underweight is a big deal for kids, but it’s often missed. The truth is, once kids slide into growth impairments, it throws a lot of other stuff off kilter for them:
- Their immune systems don’t work as well. They get sick more often, stay sick longer, and have more complications from infections than kids in healthy growth status.
- Kids struggle more to behave, learn, focus, or sleep, and will often experience more anxiety, less self regulation, and more mood swings.
- Growth impairments will skew many lab tests, leading to rabbit-hole searches for a cause, or to prescription drug strategies that aren’t needed.
- Thyroid lab tests, metabolic panel labs, urine nutritional microbial and organic acid (OAT test),and liver function measures can drift out of range, even with mild but chronic growth impairments.
Often, literally, kids just need more food, better food, different food, or different macro ratios. But unless a careful assessment is made of growth pattern, growth history, and food intake, this simple fix is overlooked. I’ve seen it countless times, with kids being given everything from stimulant or anxiety meds, to reflux meds, complex detox protocols, or virtually useless high potency supplement protocols – all to fix problems caused by simply not eating enough replenishing food.
If your child is underweight, these functional shifts can happen, even with mild or moderate growth impairments. In other words, kids don’t have to be severely underweight for this stuff to go wrong.
When kids finally hit bottom with that failure to thrive (FTT) status – meaning they fell to fifth percentile for weight for age on the growth chart – this circumstance in itself will create a leaky gut. Many parents ask me about leaky gut, and use restricted diets in hopes of fixing this. But, without enough nutrients and energy from food for the child’s gut wall to maintain its integrity, it can break down and become more leaky. So, it’s important that kids avoid lapsing into underweight status, just as it’s important that they avoid obesity. Many circumstances may injure gut tissue and create the leaky gut scenario – and being underweight is one of them. The younger a child is, the more vulnerable they are, when dropping off expected growth pattern.
Pediatric providers generally won’t intervene on or even mention a lagging growth pattern unless your child is really, really underweight, as in – heading for the very bottom of the growth chart. Why not? There are several reasons why this can be true:
- Your insurance may not pay your doctor to intervene on a growth impairment other than failure to thrive (FTT), a severe and entrenched problem in which a child has fallen to below the fifth percentile for weight for age.
- Your doctor may not know that dropping just fifteen percentile points off expected growth pattern, for either weight or stature, can mean that your child is underweight or undernourished.
- Your pediatrician probably doesn’t know how to calculate your child’s ideal body weight, expected weight, or expected height, doesn’t have time to do it, and doesn’t know how to calculate how much food or what macro ratios are needed to maintain healthy growth and gain for your child’s case.
- Your doctor doesn’t have time to scrutinize, integrate and explain all the growth data in a brief visit, including all the things that impact growth, from your kids’ food intakes to energy level to genetics.
- Your doctor isn’t sure how to help you fix the problem, or why it’s happening in the first place, if they notice it.
- Your doctor lacks training in nutrition and how to use food for health.
Because I work with kids with problems like allergy, autism, severe picky eating, FPIES, inflammatory bowel conditions, or all sorts of circumstances in which they don’t eat well, it’s common for me to find that a child is underweight. Many parents who contact me have placed their kids on over-restricted special diets on their own, and don’t realize their kids are underfed and malnourished, even with all the best efforts at feeding well.
It’s a big relief to know exactly what and how much food your child needs to grow, feel, and function better. Usually, parents are downright surprised at what a difference something as simple as the right food intake makes for their kids. This quote is straight out of clinic today from a mom regarding her fifth grader. Before nutrition intervention, he had severe attention and focus issues for which he’d been unsuccessfully medicated. He had accidents at school (smearing, pooping in his pants). He got sick often with colds. He was unhappy or frustrated often. After nutrition care, mom said this:
“Looks super healthy, I’ve never seen him this healthy. He seems more like a regular kid. He is thriving. He is growing like a weed. He is happy.”
This boy is off stimulant medication, using the bathroom independently and not having accidents, and has not had any infections for months, for the first time in his life.
What are our pediatricians trained to do for these problems? Give methylphenidate (stimulants like Focalin, Ritalin, etc) for inattention and hyperactivity; Miralax for the constipation; antibiotics for the infections; and a “he’s just a little skinny” shrug for the regression we found, for this child’s expected weight for age. We can do much better!
Start with this calculator to find your child’s weight for age, height for age, and body mass index (BMI) for age. This calculator works for children over age 2 years. Look for a BMI result above the tenth percentile. Use current measurements for your child; being off by even a quarter inch for height or a couple pounds for weight can skew results quite a bit. While physicians are trained to take action once a child drops below the fifth percentile for weight for age, in my experience, I find that kids simply function and feel better if they maintain a BMI at least at the tenth percentile, even if they are of a tall lean build. Ideally, look for a BMI that lands somewhere between the 20th and 75th percentiles. There are many other pieces of a proper growth assessment that pediatric nutrition professionals can do, but knowing if your child is underweight can start by getting their body mass index. If you’d like to stay in touch with resources at Nutrition Care For Children, contact me here to let me know. Thanks for stopping by!
Hi, Judy! I stumbled upon your website after a Google search (of which I’ve done more than I care to admit over the last almost 18 months). I have an ENTIRE saga I could write about my daughter’s life from about 6 weeks old up until this point. She was born 7lb3oz at 40w0d, EBF, gained weight beautifully until she got Covid at 6 weeks old. Handled Covid very well, but then began to lag slightly behind in her weight gain by her 2 month check up.
By that point, she nursed less vigorously. Eventually, refused bottles from 3 months on when I went back to work. Bottle refusal continued but she came around after lots of persistence and distraction techniques.
To sum up the main points:
– slow weight gain (up to almost 70th% at 6 weeks old and has consistently decreased %iles to now barely hanging onto the 5th at 19 months)
– awful reflux starting around 2-3 months
– constipation (was told BMs every 5-10 days were “normal” for EBF baby — except now here we are dependent on Miralax to get a somewhat normal stool pattern)
– lip & tongue tie revision at 3 months
– refusal of purees/solids
– feeding therapy with some improvement but still has very poor oral intake overall
– suspected swallowing issues due to occasional coughing with sips of water, but would not participate with swallow study attempted last month
– wakes through the night to nurse
– only drinks water from a cup, refuses any kind of milk other than breastmilk via nursing or bottle
I’ve tried probiotics, cutting out dairy. CBC is normal/no anemia. CMP showed very slight elevation in AST/ALT at 6 weeks old and AST at 15 months old, otherwise normal. She is extremely picky with eating in terms of what she will eat and how much (seems to struggle with coordinating chewing/swallowing) so I’m afraid a dietary overhaul is going to cause her to lose weight and worsen our problem.
I realize that’s a lot of info but if you could PLEASE point me in the right direction, I have been desperate for answers for so long!
By “2 month check up” I wonder if you mean “vaccinations”. If she was given those right on the heels of a covid bout, then all bets are off here. Research has been unfolding on how covid itself can affect gut microbiome and/or gut tissue. Add to this the challenge of the 20 different antigens given in six needles at this visit and you’ve got a cocktail with high potential to trigger lasting effects on digestion, inflammation, or microbiome evolution. Good to see generally normal findings on her blood work so far – the liver enzymes may be secondary to her medication use and/or to a latent viral burden from covid or shots. Deeper digging into her gut microbiome status would be my first step and for this I would recommend a GI MAP from Diagnostic Solutions Lab.
Actually, I delayed her 2 month vaccinations because when we went in for that appointment, she was in the starting phases of another URI. I will look into the GI MAP, thanks!
Hi!
My son is 11 and he is underweight. Unfortunately, below the first percentile. We started with a functional medicine doctor and he has a leaky gut. He has been on supplements since March and gained four pounds between March and May but did not gain any over the summer. Our doctor added more supplements and he is back on protein shakes but he is very picky about eating. I am super worried because it is quiet obvious that he is small and skinny than the rest of his peers. Please advise. I am desperate to help him grow.
Should we go to Children’s hospital in Denver?
Hi Tsvetana, good for you for digging deeper. What your functional medicine doctor may not know how to do is calculate necessary food intake for growth and gain, given your son’s growth failure status. There are well studied rubrics for this and this is one of the tools in the quiver for a registered dietitian. Your son may need triple the calories per pound, than a same age peer who is not in growth failure. Gaining four pounds in three months is a good start but too slow still, and a plateau over summer means you haven’t quite got there. Protein does not do much to help children in growth failure for weight gain. It is very important, but in itself is a poor and inefficient fuel source. If your son isn’t getting enough total calories, and is relying on a big protein intake with high fat and low carbs, this will discourage weight gain. Give about half his food intake as “clean carbs” – that is, unprocessed whole starches like squash, potato with skins, any tolerable grains, whole fresh fruit and vegetables, and cooked vegetables. Supplements don’t help weight gain either, unless they are medical foods or formulas specific for that purpose. These can help – but food is what is missing here. He also needs a reliably comfortable pattern of formed daily stools to indicate that he is absorbing food well.
My grandson was born w a diaphragmatic hernia is going to be 5. He has had difficulty eating from day one. Still on a bottle- elecare eating only purée baby food when we can get him to eat anything. He is not talking, not toilet trained and doesn’t sleep at night. Has been to every specialist and had every test under the sun. We are so desperate – can you please help. Have read your book milk addicted and sounds so much like him. Thank you
Hi Nancy, please reach out to my assistant at 720-272-7105 to set up an appointment.
Hi Judy! I’m excited to have found your website! I had a question for you regarding percentiles…..when you are diagnosing a child as underweight, are you using the CDC or WHO data? Our doctor uses the CDC chart, and my daughter fluctuates between the 5th and 9th percentile for weight (but is in the 28th percentile for height). I’m very slim myself, and we eat a diet without a lot of “junk food” (I try to incorporate healthy fats as much as I can).
Anyway, I just wonder if the CDC chart is always the right way to go….seems like Americans are so much heavier than people in other countries 🙂
-Danielle
Since 2010, the American Academy of Pediatrics has suggested using WHO charts for kids age 0-2 and CDC charts after that age. I follow this guideline, unless a child is of another ethnicity that warrants a different chart, has Down’s syndrome (different chart), or was premature. All of these factor in to which chart clinicians use. I will also check which chart the child’s GI or pediatrician has been using to keep continuity. Your daughter’s growth pattern may be fine, but to know for sure, more than a chart is needed. Her growth history since birth including birth weight and length, health history, and food diary would be a start for me to be able to know if this pattern is healthy for her.
Thank you for your response, Judy! Hope one day we can work with you 🙂
Hello,
I have a 28 month old boy who has always “struggled” with eating and sleeping. As a baby he nursed what seemed constantly to me and woke every 2 hours. Now we are struggling to feed as he is so picky, and may like one thing one day and think it’s the most disgusting thing next day. He still wakes 1-2 times at night and we are currently dealing with a Jekyll and Hyde tantrum situation. He was diagnosed with a short frenulum as baby but I opted not to have it cut. Doctor says he’s fine but only 25 pounds and you can count his ribs. Any suggestions? I like your smoothie options…
Hi Sonia, hmm well.. This places your son at about the 7th percentile for weight for age. Is this “fine” – ? Not if he began life at or above the 20th percentile. In that case, he has a clear growth regression from picky eating. This affects behavior, sleep, and cognitive development. There are usually underlying factors that contribute to picky eating (including short frenulum) – but these are readily sorted and corrected with nutrition intervention. Smoothies can be useful as they are so easy to make calorie and nutrient dense for underweight kids. But what would be really great here is to find out why your son’s appetite is so mercurial and unreliable – and fix that – as well as identify what are – in his case – the right choices to put into stuff like smoothies. Let me know if you’d like more help, and we can get started (I work remotely or in person).
Do you know of anyone I could go to in Charleston SC for my son?
Hi Ashley, I don’t know of resources in your area but I do work with families remotely quite often, via phone or Skype. Click the appointments tab above to see options, pricing and calendar. As long as I have documentation and history that I need, this can work fine. Be sure to let your local doctor know your concerns too.
I’m curious if there is anything nutritionally I can do to help my son. What information would you need from me? He is 2. I see I can schedule a 10-minute appointment…
Hi Stacy, if you schedule a 10 minute slot, the calendar auto-replies with details about this. You don’t need to fill all the paperwork out for the 10 minute slot, but it gives you a preview of everything I need.