Teenagers adopt 'cut and bulk' routines and extreme diets as social media fuels demand for sculpted bodies
Young people are following intensive training cycles, restrictive eating plans and online advice to achieve defined muscles, prompting warnings from health professionals about growth and mental-health risks.
A growing number of teenagers are adopting "cut and bulk" training cycles and restrictive diets to achieve highly defined muscular physiques, driven in large part by social media content, interviews with young gym users and health experts show.
The cut-and-bulk approach involves deliberately increasing calorie intake for weeks to add muscle and some body fat (the "bulk"), then sharply reducing calories to lose fat and reveal greater muscle definition (the "cut"). Hashtags such as #shreddedphysique have been viewed billions of times, and videos show boys as young as 13 and 14 flexing in school toilets and posting staged gym content. For some participants it is a light commitment — occasional weights, more protein and sport — but for others it has become a near-daily regimen involving intense training, precise calorie counting and strict dietary rules.
Fourteen-year-old George Holland described how the hobby that began at 11 has become competitive. He is the youngest competitor to win a bronze medal in the under-19s division at a National Amateur Body-Builders' Association final; he trains with a former Mr Universe and posts regularly to more than 140,000 social followers. Holland said he started with a 10kg limit at a local leisure centre — the heaviest permitted for under-16s at that facility — but later moved to a gym where he could increase loads and train with older lifters. He reported current lifts including a 140kg bench press, a 180kg squat and a 200kg deadlift, and said he cycles between a 4,100-calorie bulking phase and a 2,200-calorie cutting phase over weeks.
George Holland and other teenagers interviewed rejected concerns that intensive gym regimes in adolescence are harmful. "I completely disagree with that, going to the gym when you are young is dead good for you," Holland said, adding that training provides discipline, fitness and mental-health benefits. He acknowledged the planning and commitment required: multiple meals a day, school attendance and regular training sessions.
Seventeen-year-old George Hazard, who began working out in lockdown on a basic home set-up, said the gym has become close to an addiction and a social pursuit with friends. Hazard, who underwent a leg-lengthening operation after being born with one leg shorter than the other, credited training with improving mobility and rehabilitation. He said social media provided a mixture of useful evidence-based guidance and less reliable content; over time he has learned to look for posts that link to studies or cite reputable sources. Hazard described practical obstacles for teens aiming to follow strict diets, noting the dependence on family meals and the difficulty of enforcing exact meal plans at home.
An 18-year-old, Nat Walney, described a different trajectory: early years of "dirty bulking" in which high-calorie, low-nutrient food predominated, followed by a shift toward more extreme eating patterns, including the carnivore approach and prolonged daily fasting. Nat said he now eats primarily raw steak, eggs and raw milk and follows a 20-hour daily fast, which he feels improves mental clarity. He also said he used AI tools such as ChatGPT for guidance at times. He acknowledged that some published advice discourages prolonged fasting and said he would change his diet if he began to feel unwell.
Health professionals caution that components of these trends can be harmful during adolescence. Children's dietician Lucy Upton said the desire to be fit is not in itself a problem, but when appearance becomes the main focus it can push teens toward extremes and amplify exposure to misleading online advice. "Too often, it's about the look, rather than what healthy really means, which comes in all shapes and sizes," she said, urging young people to check whether online content comes from qualified professionals and to be wary when products are being promoted.
Sam Grady-Graham, a GB Boxing coach, advised against very restrictive eating regimes for teenagers. "The rate of growth between 12 and 18 is exponential," he said. "The body needs a full and nutritious diet to fuel it." He recommended a balanced diet drawing on the main food groups and gradual progression in training intensity, prioritising movement quality and foundational technique over immediate visible gains.
Experts also warn about specific medical and psychological risks. Some sports nutritionists say repeated cycles of bulking and cutting during key developmental years could affect hormone balance, growth and long-term health. Restrictive eating, extreme calorie deficits or prolonged fasting can adversely affect organ function and are linked to disordered eating patterns, including muscle dysmorphia — a preoccupation with being insufficiently muscular despite appearances. While intermittent fasting has shown some benefits in studies involving adults, clinicians say those results do not necessarily apply to adolescents, who have greater energy and nutrient needs for growth.
The role of social media and algorithmically promoted content is a recurrent concern. Young people can encounter a large volume of training programmes, dietary protocols and anecdotal success stories that often lack clinical validation. Upton and others advise caution when teens use AI or unregulated online sources for tailored diet or exercise plans, noting that these tools may produce inaccurate, incomplete or unsafe recommendations.
Parents, coaches and health professionals have a role in spotting harmful patterns and guiding safer practices. Professionals urge that young people who want to improve strength and fitness should focus on balanced nutrition, age-appropriate progressive training, proper technique, adequate rest and, where appropriate, supervision by qualified coaches or medical practitioners. Those experiencing anxiety about body image, obsessive dieting or physical symptoms such as fatigue, dizziness or persistent acne should be evaluated by health services.
The teenagers interviewed said fitness and appearance drive their choices in different ways, with some seeking competitive success and others looking for personal confidence or rehabilitation. Health experts say encouraging realistic expectations, critical appraisal of online advice and support for whole-person wellbeing can reduce the risk of harm while allowing young people to pursue healthy activity and strength-building in safer ways.
