Nearly 1 in 6 kids and teens who started a GLP-1 medication were diagnosed with a new nutritional deficiency within a year, according to a new U.S. study. Even more striking: only about 5% got any nutrition counseling in the first month of treatment.
The research, published September 17, 2026, in the journal Childhood Obesity, is one of the first large looks at what happens to young people’s nutrition after they start these drugs. If your family is weighing GLP-1 for kids, or your teen is already on one, this isn’t a reason to panic. It’s a reason to ask better questions. Here’s what the study found, what it can’t tell us, and a simple plan to bring to your next appointment.
What the New Study on GLP-1 for Kids Found
Researchers led by senior author Justin Ryder, PhD, of Ann & Robert H. Lurie Children’s Hospital of Chicago and Northwestern University Feinberg School of Medicine, dug into national insurance claims data from 2017 to 2022. That database covered more than 100 million patients.
From it, they identified 2,031 young people ages 10 to 17 who started a GLP-1 medication and had no prior diagnosis of a nutritional deficiency. Here are the headline numbers, as reported by the Lurie Children’s news release and The Pharmaceutical Journal:
- 10.2% were diagnosed with at least one nutritional deficiency within 180 days of starting treatment.
- 16.8% – nearly 1 in 6 – had one within a year.
- Vitamin D deficiency was the most common, diagnosed in 12.4% of patients within a year.
- Nutritional anemia was the most common deficiency-related complication, affecting about 1.55% after one year.
The authors said these results line up with earlier research in adults that linked GLP-1 use to eating less and a higher risk of falling short on certain micronutrients.
Who Was in the Study – and Which Drugs They Took
This wasn’t only a weight-loss group. According to The Pharmaceutical Journal, about 62.6% of the young patients had obesity, 67.2% had a type 2 diabetes diagnosis, and 5.1% had prediabetes. (Those groups overlap, since many kids had more than one diagnosis.) The average age was 15, and about 61.5% were female.
The drug mix may surprise parents who mostly hear about newer medications on the news:
- Liraglutide: 78.6%
- Dulaglutide: 10.4%
- Semaglutide: 9.1%
That makes sense for the time period. The data run through 2022, before newer options were widely used in teens. So the findings may not map perfectly onto today’s prescriptions – something to keep in mind.
Why Nutrition Matters So Much During the Teen Years
Adolescence is a growth sprint, which is exactly why doctors approach GLP-1 for kids differently than for adults. Bones are building density, bodies are going through puberty, and nutritional needs are high. A medication that turns down appetite can make it harder to hit those targets, even when a child is otherwise doing everything right.
“As appropriate pediatric use of GLP-1s becomes more widespread, we need to understand the risks during periods of rapid growth and pubertal development,” Ryder said in the release. “Nutrients such as vitamin D, iron and calcium are of particular concern during adolescence, when deficiencies may have lasting implications for skeletal health and overall development.”
For context, the National Institutes of Health’s Office of Dietary Supplements recommends 600 IU (15 mcg) of vitamin D a day for kids and teens ages 1 to 18. It also notes that people with obesity may need more vitamin D than others. For calcium, the ODS lists 1,300 mg a day as the target for ages 9 to 18 – more than most adults need.
The Real Gap: Nutrition Support for GLP-1 for Kids
The most actionable finding isn’t about the drugs at all. It’s about what happened around them.
“Nutritional support needs to play a critical role once treatment with a GLP-1 medication is initiated,” Ryder said. “In our study, however, we found that only 5% of patients received nutritional counseling within 30 days of GLP-1 treatment and less than 25% received nutritional counseling within 6 months.”
In other words, most families in this data set weren’t getting a dietitian visit or structured nutrition guidance when treatment began. That’s a system gap, not a parenting failure. Many families simply aren’t offered the referral, or insurance and scheduling get in the way.
The researchers are calling for a shift toward “proactive nutritional management when GLP-1s are prescribed to children, as opposed to waiting until a nutritional deficiency is diagnosed,” as Ryder put it.
For comparison, a UK pharmacy leader quoted by The Pharmaceutical Journal, Sukhi Basra of the National Pharmacy Association, noted that in the UK, liraglutide is the only one of these drugs licensed for adolescents, and only through specialist pediatric weight-management services where dietetic support is built in from day one.
What This Study Can’t Tell Us
Before drawing big conclusions, it helps to know the limits:
- It’s observational. The study shows an association between starting a GLP-1 and later deficiency diagnoses. It doesn’t prove the medication caused them.
- It’s based on insurance claims. A deficiency only shows up if someone tested for it and coded it. Some kids may have had undiagnosed deficiencies before treatment, and some deficiencies after treatment may have been missed.
- Testing may have increased. Kids starting a new medication often get more lab work, which can uncover problems that were already there.
- There’s no comparison to similar kids not on GLP-1s in the published summaries we reviewed, so we can’t say how much higher the risk is than baseline.
- The drug mix is dated. Most patients took liraglutide, and the data end in 2022.
None of that makes the findings unimportant, and it doesn’t settle the bigger debate over GLP-1 for kids either. It just means the right response is closer monitoring and support – not stopping a medication on your own.
Questions to Ask Your Child’s Care Team About GLP-1 for Kids
If your child is on a GLP-1, or you’re considering one, these questions can help you walk out of the appointment with a plan:
- “Should we check vitamin D, iron and other levels before starting, and when should we recheck?” A baseline makes it easier to spot changes later.
- “Can we get a referral to a registered dietitian?” Ideally early, not after a problem shows up.
- “How much protein, calcium and vitamin D should my child aim for while their appetite is lower?”
- “Should my child take a supplement, and at what dose?” Don’t start high-dose supplements without guidance – the ODS notes vitamin D can be harmful in excess.
- “What signs of low iron or low vitamin D should we watch for?” Things like unusual tiredness are worth mentioning.
- “How will we track growth and bone health over time?”
Easy Food Ideas When Appetite Is Low
When a medication shrinks appetite, every bite counts more. The ideas below are general healthy-eating guidance, not advice from the study, and your child’s care team or dietitian can tailor them.
Vitamin D
Very few foods naturally contain much vitamin D, so fortified foods do a lot of the work. According to the ODS, almost all U.S. milk is fortified with about 120 IU per cup, and many soy, almond and oat milks are too. Fatty fish like salmon, trout and tuna are among the best natural sources. Eggs, some fortified cereals and UV-exposed mushrooms help a little.
Calcium
Milk, yogurt and cheese are the classic picks. Fortified plant milks, calcium-set tofu and leafy greens can round things out for kids who skip dairy.
Iron
Lean meats, beans, lentils and iron-fortified cereals are solid options. Pairing plant-based iron with a vitamin C food, like berries, oranges or bell peppers, can help the body absorb it.
Protein
Protein helps protect muscle during weight change. Small, frequent options are easier when kids feel full quickly: Greek yogurt, eggs, cheese sticks, milk-based smoothies, chicken, beans or nut butter on whole-grain toast.
One more tip: keep the tone neutral at home. Kids on these medications are managing a medical condition. Focusing on energy, strength and feeling good – rather than weight or “good” and “bad” foods – tends to work better for everyone.
The Bottom Line for Parents
GLP-1 medications can be an appropriate, doctor-guided tool for some kids and teens. This study doesn’t change that. What it changes is the checklist: GLP-1 for kids should come with a nutrition plan, not just a prescription. What it does show is that nutrition support often lags behind the prescription, and that vitamin D in particular deserves attention.
Your next step: If your child is on or starting a GLP-1, talk to your pediatrician this month about baseline labs, a dietitian referral and a follow-up schedule. Don’t stop or change a medication without talking to their doctor first.
Want the bigger picture? Read our breakdown of the semaglutide for children trial in kids ages 6 to 11, and catch up on new GLP-1 research, including the real catch. Stay with USA One News for more research-backed parenting coverage.
