The influencers and the algorithms fill the void
In Madrid this week, Spanish pediatricians raised an alarm that speaks to something larger than nutrition: in the absence of trusted guides, children and their parents are turning to algorithms and influencers to answer questions that once belonged to medicine. The trends arriving at family dinner tables — plant-based milks for infants, gluten-free diets for healthy teenagers, intermittent fasting adopted from a video — carry real risks of deficiency and disorder during the years when the body is most vulnerable. Behind the clinical warnings lies a structural wound: nearly two million Spanish children have no dedicated pediatrician, leaving a void that the internet is eager to fill.
- Teenagers are eliminating entire food groups based on TikTok recommendations and AI chatbots, with no medical supervision during the most nutritionally critical years of their development.
- Infants are being given plant-based milk substitutes — including rice milk, which contains arsenic levels dangerous for children under three — by well-meaning parents who believe cow's milk is harmful.
- Pediatricians warn that unsupervised restrictive diets in adolescents are not merely nutritional risks but potential gateways to serious eating disorders with lifelong consequences.
- Spain's pediatrician shortage has deepened to 30% of primary care positions vacant in 2024, leaving 1.9 million children without a dedicated doctor to counter the misinformation they encounter online.
- The health halo surrounding plant-based products is misleading families: ultra-processed plant-based snacks and burgers are still high in sugar and saturated fat, regardless of their branding.
At a Madrid conference this week, Marta Castell, who coordinates pediatric gastroenterology and nutrition for Spain's primary care pediatricians association, delivered a warning that has grown impossible to ignore: social media nutrition trends are reaching children's plates faster than doctors can respond.
The pattern she described is both simple and alarming. Teenagers are cutting out gluten without any medical diagnosis, restricting calories to lose weight rapidly, or swapping cow's milk for oat milk — all because an influencer recommended it or an AI chatbot suggested it. No professional guided these decisions. No one is following up. Castell noted that much of the nutrition information circulating on social media is unverified, and that adolescents are experimenting with their bodies during the years when proper nourishment matters most. Beyond nutritional gaps, she warned, unsupervised restrictive diets can become the first step toward eating disorders — conditions with consequences that extend long into adulthood.
Younger children are not spared. Some parents have replaced cow's milk with plant-based alternatives even for infants under two, a substitution that is nutritionally inadequate at that age. Rice milk, one popular option, contains arsenic levels high enough that pediatricians advise against it for children under three. Among older children, parents impose total sugar bans or shift the family to plant-based diets with genuine good intentions — but plant-based burgers and snack bars remain ultra-processed foods, their health halo obscuring what they actually contain.
Deepening the crisis is a structural collapse in pediatric care. Spain's share of vacant primary care pediatrician positions rose from 26% in 2018 to 30% in 2024, leaving 1.9 million children without a dedicated physician. The association's president, Pedro Gorrotxategi, pointed to a training pipeline that steers residents toward hospitals — only 22% of final-year residents train in primary care. The result is a vacuum that algorithms and influencers are filling by default.
Marta Castell, who coordinates the pediatric gastroenterology and nutrition division of Spain's primary care pediatricians association, stood before a Madrid conference this week with a warning that has become impossible to ignore: the nutrition trends flooding social media are reaching children's dinner tables faster than doctors can intervene.
The problem is straightforward but insidious. Teenagers arrive at clinics having eliminated gluten from their diets despite having no medical reason to do so. Others have adopted severe calorie restriction to lose weight quickly. Some have replaced cow's milk with oat milk, all because an influencer on TikTok mentioned it, or because an AI chatbot suggested it. None of these decisions came with professional oversight. None came with follow-up care.
"We're seeing more and more people who aren't healthcare professionals talking on social media about important topics like plant-based drinks and nutrition trends like intermittent fasting," Castell said, "and much of that information isn't verified." The consequence is that adolescents are experimenting with their own bodies during the most nutritionally critical years of their lives, without anyone checking whether they're getting what they need to grow.
The risks run deeper than simple nutritional gaps. Castell emphasized that unsupervised restrictive diets in teenagers can become the gateway to eating disorders—conditions with long-term consequences that extend far beyond childhood. A teenager who cuts out food groups because a video suggested it might be taking the first step toward a serious psychiatric illness.
But the problem doesn't stop with adolescents. Parents are making equally concerning choices for younger children. Some have decided that cow's milk is harmful and have replaced it entirely with plant-based alternatives, even for infants under two years old. This substitution, Castell explained, is nutritionally inadequate at that age. Some plant-based options are actively dangerous: rice milk, for instance, contains arsenic levels high enough that pediatricians recommend against it for children under three.
As children grow older, new trends emerge in the clinic. Parents impose blanket bans on all sugar. They shift their children to plant-based diets. The intentions are often good—parents want their children to eat well. But the execution frequently backfires. Plant-based hamburgers are still hamburgers. Plant-based snack bars are still ultra-processed foods loaded with sugar and saturated fat. The health halo around these products masks what they actually are.
Underlying all of this is a structural crisis that makes the problem worse. Spain's pediatrician shortage has worsened dramatically. In 2018, about 26 percent of primary care pediatrician positions sat vacant. By 2024, that figure had climbed to 30 percent. Across the country, 1.9 million children now have no dedicated pediatrician. Pedro Gorrotxategi, president of the pediatricians association, pointed to a training system that funnels medical residents toward hospital work rather than primary care—only 22 percent of final-year residents train in primary care settings. The result is that even families who want professional guidance often cannot find a pediatrician to provide it. The influencers and the algorithms fill the void.
Citações Notáveis
We're seeing more and more people who aren't healthcare professionals talking on social media about important topics like plant-based drinks and nutrition trends, and much of that information isn't verified.— Marta Castell, pediatric gastroenterology and nutrition coordinator
Unsupervised restrictive diets in adolescents without professional supervision and dietary guidance carry significant risk and can be a precursor to eating disorders.— Marta Castell
A Conversa do Hearth Outra perspectiva sobre a história
Why does a TikTok trend about oat milk matter enough to alarm an entire medical association?
Because a teenager doesn't know they're in the middle of bone development. They don't know that switching milk sources without replacement can mean calcium deficiency that affects them for decades. They just know someone they trust online said it was better.
But surely parents are still involved in what their kids eat?
Some are. But many are following the same trends. If a parent believes cow's milk is harmful, they're not going to push back when their teenager refuses it. And if a parent is getting nutrition advice from the same sources their teenager is, there's no adult in the room with actual medical knowledge.
You mentioned eating disorders. How does avoiding gluten lead to that?
It often doesn't directly. But the behavior—the restriction, the rule-making, the sense of control through food—that's the architecture of an eating disorder. Once a teenager learns they can feel powerful by saying no to food, it's easy to expand that into something much darker.
What about the plant-based milk for infants? That seems like a clear-cut mistake.
It does to us. But a parent reads that cow's milk causes inflammation, or that it's unnatural, and suddenly the thing they were told to give their baby seems dangerous. No one's there to say, "That's not true for your six-month-old." The pediatrician's office is full or doesn't exist.
So the shortage of pediatricians is making this worse?
It's making it impossible to fix. You can't counter misinformation at scale if there's no one to deliver accurate information when families actually need it.