Gen Z’s Dangerous Quest for Gains

WHEN ELI WEISS was 15, his mom, Claire, took him to his pediatrician. Eli had been experiencing back pain, the kind that started as an annoyance but worsened over the course of several weeks until Eli, tears in his eyes, told Claire his back hurt so badly that he didn’t want to get up off the couch.

During that autumn 2023 drive to the doctor’s office through their neighborhood of Maplewood, New Jersey, Claire wasn’t sure why Eli hurt so much. But she suspected that his discomfort might have to do with how much time he had been spending at the gym.

Eli was, after all, going to the gym a lot. He had transformed himself from a lean, all-knees-and-elbows middle schooler into a high schooler with flex. Even his hair, once a tight tangle of white-blond curls, had grown bigger and prouder. Eli had been lifting weights in the Weiss’s home gym since age 13, but only a few times a week, max. He preferred skateboarding and snowboarding.

But when he was 14, Eli joined the gym across from his school. He began following more fitness accounts on Instagram and TikTok. His social feeds transformed from kickflips to squat tips. He was at the gym almost every day (always lifting, never cardio), sometimes for two and a half hours, and he knocked back protein shakes when he came home. He was seeing results, too. In two years, he’d gone from 5′7″ and 125 pounds to 6′, 160 pounds.

Some of the weight was due to his natural growth, yes, but Eli was also strong. He bragged to Claire and Jeremy, his dad, that he had hit 255 on the squat rack and 155 on the bench. He’d troll his parents with photos of the massive bodybuilders on his social feed, saying, God look at their bodies. I want my body to look like that. “He would constantly have his shirt off, flexing all the time,” says Claire. “But it always seemed like a joke—until it didn’t.”

During that car ride to the pediatrician, Eli was quiet. In the doctor’s office, Claire and Eli received the news together. “His pediatrician said his muscles were growing faster than his bones,” Claire says. The doctor explained to Eli that certain bodies aren’t made to be big, including his. To keep pushing himself to lift more weight wasn’t safe. Eli felt defeated. “I guess I just kind of always believed that I was able to overcome and reach those fitness goals,” says Eli. “But she was right—and it just sucked that she was right.” Had Eli kept pushing through the pain, he could have suffered a muscle strain, a hernia, a slipped disc, or even a back injury that might have harmed his growth.

And that’s just the physical damage. Perhaps even more worrisome is what some experts see as an alarming mental health trend among boys who want to build more muscle. Researchers even have a name for it: muscle dysmorphia.

The disorder, which also goes by “bigorexia,” often involves weight training obsessively, taking supplements, skipping meals, withdrawing from friends and family, and having a preoccupation with muscle-centric social media content. The risks are scary: disordered eating, extreme fatigue, malnutrition, and an increased risk for anxiety and depression.

While current research shows that only about 2 percent of boys have been diagnosed with muscle dysmorphia, experts speculate that the number of undiagnosed is far higher. Experts cite a Wild West social media culture that serves boys ever-extreme fitness content and an unregulated supplement market that makes it too easy for underage kids to buy dangerous pills and powders they don’t need.

Unfortunately, parents often learn too late about the pressures and pain boys face. Eli’s dad knows this all too well and regrets not seeing the warning signs in his son earlier. “I told him, ‘You’re just having growing pains,’” Jeremy says. “I’d tell him to use the Theragun or muscle cream. Because when I was his age, I had tons of body pain from growing, but when I was his age, I wasn’t working out at the gym.”

Jeremy, like all Gen X parents, also didn’t grow up with social media or easy access to supplements, either. Experts say this generational gap makes things even more difficult for parents. “The biggest change from early to middle adolescence is that kids are more influenced now by their peers than by their parents,” says Jason Nagata, MD, a pediatrician specializing in eating disorders at the UCSF Benioff Children’s Hospitals. And, Dr. Nagata says, peers are kids not just from school, but from Instagram, TikTok, and Snapchat. “Social media is this exclusive place where peers and media can form into one and impact teenagers and their body image. Unfortunately, social media is a huge driver for many of our patients and how they got to their eating disorder and body dissatisfaction.”

But that doesn’t mean parents, caregivers, and coaches can’t help boys navigate this new world. Here’s what they need to know now.

AFTER ELI STARTED lifting regularly at 14, he began to like and follow more fitness content. Gradually, his social feeds changed from the skateboarders he had started following when he first got into social media at 13 to bodybuilders. During that year, Eli started seeking out short-burst workout videos on TikTok, which he would then see more of on his feed.

He wasn’t passively engaging with this content, either. He’d take the advice and inspiration from workout videos to push harder and heavier at the gym. He’d also model bodybuilding poses (the front double biceps was a favorite of his) in the mirror and around the house. What Eli was experiencing were the effects of algorithm ranking, a tool that social media companies leverage to feed stickier content to their users. That content holds the attention of the user longer, which leads to more ad revenue for the company.

Teens, especially, are susceptible to this manipulation, says S. Bryn Austin, ScD, a Harvard professor of social and behavioral sciences who studies boys, social media, and body image. “Through the teen years, the brain is going through major changes. What develops first is emotional response, and part of that is social reward,” says Austin. “So what we have is a lopsided brain development that makes them particularly vulnerable to the types of techniques that social media platforms are using to draw them in, hook them, and keep them there.” Those techniques include notifications from friends and influencers, the dopamine spike related to receiving a comment or like, and the endless scroll of content. Algorithmic ranking can actually change a user’s behavior IRL, says Austin.

Facebook (remember that?) pioneered the first algorithm back in 2009. But it wasn’t until 2016 that Twitter and Instagram began filling feeds not with what users wanted to see but with what those platforms thought users wanted to see—while also serving them ads. TikTok, which launched the same year, perfected the art of cultivating a “For You” page, built entirely from eyeball-attracting algorithmic-ranking content. In 2022, Snapchat launched a hit series called Maxed, which featured short episodes about adolescents trying to muscle up or slim down.

But what’s good for the tech company isn’t always great for its users. Last year, researchers reviewed 32 studies on the effects of algorithm-driven social media on mental health. They found that kids who used social media were far more likely to report feeling dissatisfied with their bodies and have eating disorders than kids who didn’t—a factor that may be contributing to the recent rise in eating disorders among children in the U.S.

On top of that, social media may also be fueling another potentially dangerous trend among teens: buying and consuming possibly risky muscle-building and weight-loss supplements.

AND WE’RE NOT talking about Flintstones vitamins. Dr. Nagata published research in 2022 that found that 55 percent of adolescent boys reported using muscle-building protein powder or shakes—and that protein supplement consumption was linked to future steroid use. A 2021 study review found that 72 percent of adolescent male athletes reported using creatine (compared with 28 percent of female athletes). According to a meta-analysis from 2024, among adolescents worldwide, the prevalence of weight-loss supplement or over-the-counter diet pill usage in their lifetime was 1 in 10.

Know that in 49 states, it’s legal for minors to go to a brick-and-mortar supplement store and buy protein powder, creatine, and fat burners. And if you’re underage and have a credit card, you can buy them online from any state.

Retailers are eager to sell to minors, too. When researchers impersonated a 15-year-old boy and called 244 health food stores across the U.S. in 2017, they found that roughly 67 percent of sales attendants recommended buying and taking creatine. (Both the American Academy of Pediatrics and the American Medical Society state that kids under 18 should not take creatine.)

Ryan Ahmed, 20, told Men’s Health that he used to order supplements online when he was a minor. His parents didn’t know. “I saw an advertisement for a product that promised I could lose weight—20 pounds in one month,” so he spent $40 of his own money to buy it. He’d seen juniors and seniors in his high school class taking similar supplements in their feeds.

Some supplement brands even market directly or indirectly to children by way of social media affiliate marketing deals. This form of shadow advertising involves a third party (a teen influencer, say) promoting a product (creatine, as one example) for a commission. To kids, these ads feel less like a hard sell than a strong suggestion.

Years later, Ahmed reconnected with some of the older students whom he saw taking supplements in their feeds. He learned that they weren’t even using the products. “At the end of the day, it was just their hard work in the gym,” Ahmed says.

The reality is that no child—as in any person under the age of 18—needs muscle-building or weight-loss supplements, says Brian St. Pierre, RD, CSCS, director of nutrition at Precision Nutrition, an exercise and performance company that works with adult and youth athletes. “In these 13-, 14-, 15-year-old boys, they’re going to be maximizing their gains just by eating well, because they’re so new to weight training,” St. Pierre says. “They don’t need any other enhancement.” Why run the risk?

The FDA doesn’t regulate supplements as it does prescription drugs. The government body has the power only to issue warnings (see: Neptune’s Fix products from this year) or pull a product from the market if that product hurts consumers (see: ephedra, circa 2004). Excessive caffeine, amphetamines, laxatives, diuretics, androgen modulates that mimic the effects of a steroid—these harmful ingredients have all been found in supplement products available to consumers, says St. Pierre. Even if a child doesn’t feel the effects of any of these ingredients, a positive test for a banned-from-sport substance can get them kicked off their team.

None of this has slowed the supplement industry from marketing products to kids or their parents. According to a recent market outlook from Future Market Insights, the category of children’s health supplements is expected to grow another 4.7 percent over the next 10 years.

A kid who still insists they need supplements should see an expert first. “I think parents need to be involved in that decision-making and oftentimes need to talk to a health-care provider to make those decisions,” says St. Pierre.

And all consumers can greatly reduce their risk by buying only supplements that carry a third-party certification from an established testing entity such as the National Sanitation Foundation (NSF), United States Pharmacopeia (USP), or Informed Choice. That way they know that the product has been checked for banned substances and that what’s advertised on the label is actually in the supplement.

THERE’S THAT OLD parenting trope that “kids need to get their energy out,” which is true, but only to a point. “If we’re talking 11-, 12-, 13-year-olds who haven’t hit puberty yet, the main benefit of exercise is body control,” St. Pierre says.

The Centers for Disease Control and Prevention currently recommends that children ages 6 to 17 participate in at least 60 minutes of moderate to vigorous activity daily. However, that activity should vary among aerobic, muscle-building, and bone-building exercise—at least three days of any activity type per week. In other words: not solely lifting big day after day.

But with some malls, movie theaters, and theme parks now restricting preteen access to their facilities (an effort to crack down on disruptive behavior), some boys like Eli are hanging out where they work out.

Between early 2023 and early 2024, the fitness industry saw overall new membership growth of 11 percent. But among Gen Z, new membership increased by 29 percent, according to a report from ABC Fitness, a company that provides tech to fitness-based businesses.

Last year, Planet Fitness, the most popular gym chain in America, offered a free summer membership to teens ages 14 to 19. The company invested more than $200 million in waived membership dues to promote youth health and wellness. It kicked off the program in May 2023 to align with Mental Health Awareness Month.

Great, say parents, who are excited to see their kids excited about health and fitness. But there’s a limit to how much kids should be training. Dr. Nagata says that some boys he sees as patients were working out in the gym upwards of five hours a day. This excessive exercise, also called “hypergymnasia,” can lead to social isolation, dehydration, and even nutritional deficiency.

“One of the other misconceptions about eating disorders and muscle dysmorphia is that they are exclusively about nutrition and dieting and weight loss,” says Dr. Nagata. “But I think it’s really under-recognized that you can actually get to really dangerous energy imbalances through excessive exercise.”

“ON SOCIAL MEDIA, I saw all these people, and I was like, ‘Ah, man, I want to look like that,ʼ” Eli says. Not in order to feel healthier, or perform better at sports, or even to attract a potential date—but to look better.

You probably know the “better” body type: bulging biceps, huge chest tapering to a lean waist, a six-pack. Iron Man. Wolverine. Captain America. “Media targeting boys is pushing out these ideas of a hypermasculinity, hyper-muscularity—something that’s not achievable for younger boys only partway through maturation,” says Austin, the Harvard social and behavioral scientist. “They don’t have the physiological ability to be a Marvel man. It can’t happen.”

Eli learned his limitations at the doctor’s office. Other boys, particularly those who struggle with more serious forms of body dysmorphia and eating disorders, don’t have the chance to learn. “Oftentimes, many young men and teenage boys have been struggling for years before they actually get referred and diagnosed [for eating disorders],” says Dr. Nagata. “Unfortunately, over 10 percent of people with eating disorders will die from the condition.”

Even in less extreme cases, boys who suffer from body dysmorphia can sustain intense and lingering mental health issues, such as low self-esteem and depression. Preoccupation with weight (gaining muscle or losing fat), skipping meals, drastic changes in diet, withdrawing from social or family events—all of these are warning signs of muscle dysmorphia. If you’re seeing these behaviors increase in frequency or intensity, your kid may need the help of a clinician.

IF ALL THIS feels demoralizing or overwhelming, we hear that. Luckily, there are increasing signs that the boys might be all right.

Since completing his physical therapy, Eli hasn’t been bothered by back pain. He’s a healthy 6′2″ and 155 pounds now. He has returned to skateboarding (as have his social feeds), and while he misses weight training sometimes, he’s realized that putting up more plates isn’t worth it. He hasn’t lifted in the past six months. In fact, his parents say that he doesn’t even really talk about lifting anymore.

The gym across the street from Eli’s high school? Jeremy says it’s still packed with teens. But there’s hope that boys might soon have more support. In April 2024, New York State enacted legislation to ban the sale of muscle-building and weight-loss supplements to minors. Other states, such as Arkansas, California, Florida, and Utah, are fighting how social media companies feed content to teens. Awareness of how to detect muscle dysmorphia and eating disorders among boys is gradually rising as diagnostic tools slowly develop.

And—not for nothing—it’s kind of awesome that boys have a drive for exercise and self-improvement through fitness. True health is about directing that drive in a positive way. “It’s great that a lot of these teenage boys are concerned about their health and want to do better and improve,” St. Pierre says. “We just want to encourage it in a way that’s going to actually help their long-term health and well-being. Whether it’s running, biking, lifting weights—the emphasis should be on eating well to nourish themselves and feel their best.”

That encouragement (and sometimes redirection) comes from parents, caregivers, teachers, and coaches who do still have influence on kids—even in a world of influencers.

Supplement animation by Cameron Sherrill.