I went into this one braced for the usual fight, the one where everyone argues about whether these drugs even work in kids. Whether they take weight off is not really the open question anymore. So I was not ready for the number that actually stopped me, and it had nothing to do with pounds. Five percent.

FOLLOW THE MONEY
Abbott makes PediaSure and Ensure, the nutrition drinks sold to fill exactly the kind of nutrient gaps this study says these children develop.
The study's funder sells the products its findings point toward. Source: Childhood Obesity, 2026

That is the share of children who got any nutrition counseling within a month of starting a GLP-1 drug, according to a study published September 23 in Childhood Obesity. Fewer than a quarter had gotten any within six months. And in that same window, nearly one in six of these kids, 16.8 percent, was diagnosed with a nutritional deficiency inside the first year. The most common was vitamin D, at 12.4 percent. It reads like almost nobody was watching.

WHAT THE CLAIMS DATA SHOWS
16.8 percent
diagnosed with a deficiency in year one
12.4 percent
low on vitamin D
5 percent
got counseling within a month
Diagnosed deficiencies and nutrition counseling among 2,031 kids aged 10 to 17 on GLP-1 drugs. Source: Childhood Obesity, 2026

The team, led by Justin Ryder at Ann & Robert H. Lurie Children’s Hospital of Chicago, pulled national insurance claims from 2017 to 2022, a pool of more than 100 million patients, and found 2,031 kids aged 10 to 17 on a GLP-1 with no deficiency already on record. Average age fifteen. Most carried an obesity diagnosis, and most were on liraglutide, the older drug sold as Victoza and Saxenda, with smaller shares on dulaglutide (Trulicity) or semaglutide (Ozempic and Wegovy).

So why would a drug aimed at appetite leave a growing teenager short on vitamins? I had to sit with the biology for a minute, and it is simpler than it sounds. These drugs work on hunger in the gut and the brain at once: they blunt the signals that say eat more and quiet the reward circuits that pull you toward the next meal, so a kid feels full on far less food. When the plate shrinks, everything on it shrinks with it. The vitamin D, the iron, the calcium, all of it drops in proportion unless someone is deliberately loading those nutrients back in. And this is happening during the exact window when the body is trying to build a skeleton meant to last a lifetime.

That is what makes this more than an adult problem in a smaller body. The teenage years are when you lay down most of your peak bone mass, and that build runs on calcium and the vitamin D that lets you absorb it. Fall short at fifteen and you may not make it up later. Ryder put the concern on the record: vitamin D, iron and calcium are “of particular concern during adolescence”, when a shortfall can carry lasting developmental effects. That is not hype. That is bone physiology.

The study’s limits cut in an uncomfortable direction. There was no comparison group of obese kids not on the drug, and obese kids already tend to run low on vitamin D because fat tissue holds onto it, so some of that 12.4 percent might have turned up anyway. But push on the other side and it gets worse, not better. This counts only diagnosed deficiencies, the ones that reached a billing code. A child who was never tested never shows up in the data at all, and with nutrition care this thin, plenty of these kids were surely never tested. The real rate is almost certainly higher than what got written down.

Then I looked at who paid for the study, and did a small double-take. The funding came from Abbott, and several co-authors work for Abbott Nutrition and Abbott Medical Devices. Abbott makes PediaSure and Ensure, the nutrition drinks sold to fill exactly the kind of nutrient gaps this study says these children develop. That does not make the finding false. The biology is sound and the concern is legitimate. But you notice the angle, the same way you would notice a sunscreen company funding the study that says you are not using enough sunscreen. And it is not a one-off: Abbott also bankrolled a 2025 study in Obesity Pillars that found the same pattern of deficiencies and muscle loss in adults on GLP-1s. There is a business in documenting a problem you happen to sell the fix for.

What bothers me more than Abbott’s math is why only 5 percent of these kids saw anyone about food in the first place. In 2023 the American Academy of Pediatrics told doctors they should offer these drugs to adolescents 12 and older with obesity, as an add-on to diet and lifestyle work, and prescriptions for teens climbed sharply afterward. What the guideline did not come with was much in the way of nutritional guardrails. And the people who wrote it were not neutral: an analysis published in The BMJ found that more than a third of the guideline’s contributors had undisclosed financial ties to obesity drugmakers, including the GLP-1 maker Novo Nordisk, a finding Children’s Health Defense also reported. Follow the money around the table and it turns almost elegant. The drugmaker profits from the prescription, a supplement maker profits from the fallout, the guideline that greenlit the whole thing was shaped in part by people the drugmakers were paying, and the only person at the table without a revenue stream is the fifteen-year-old whose bones are being built, or not, right now.

The harm is not purely theoretical, either, though the clearest example so far is a single case: a 2025 report in BMC Neurology documented neurological complications in an adult after rapid GLP-1 weight loss combined with nutritional deficiency. Starve the raw materials and the nervous system notices. One case is not a pattern, but it is a warning shot.

I am not against these drugs for the kids who genuinely need them. What I am against is handing a growing child a powerful appetite suppressor and treating nutrition as an afterthought, something you get to only after a deficiency surfaces in a claims database a year later. If it were my kid, I would not sign off on a GLP-1 for a teenager without a baseline vitamin D, iron, and calcium panel and a real dietitian in the room from day one, not the day after something breaks.

Sources

  1. Childhood Obesity – Nutritional Deficiencies, Complications, and Nutrition Therapy/Counseling in Pediatric Patients Using GLP-1 Receptor Agonists (2026)
  2. EurekAlert – GLP-1s linked to nutritional deficiencies in children (study release)
  3. ScienceDaily – GLP-1 drugs linked to nutritional deficiencies in nearly 1 in 6 children (Sept 2026)
  4. STAT News – Study of GLP-1 guidelines for teens points to potential for influence from drugmakers (2025)
  5. Pediatrics / AAP – GLP-1 Receptor Agonists in Pediatric and Adolescent Obesity
  6. CDC MMWR – Prescriptions for Obesity Medications Among Adolescents Aged 12–17, United States, 2018–2023
  7. Obesity Pillars (2025) – Abbott-funded study of nutritional deficiencies and muscle loss in adults on GLP-1 receptor agonists
  8. Children’s Health Defense – AAP members with ties to GLP-1 drugmakers helped write weight-loss drug guidelines for kids
  9. Diabetes, Obesity and Metabolism (2021) – Semaglutide 2.4 mg on energy intake, appetite, control of eating, and gastric emptying
  10. BMC Neurology (2025) – Neurological complications associated with rapid weight loss and nutritional deficiencies following GLP-1 agonist use
  11. Abbott – Nutrition products and solutions (PediaSure, Ensure)