New Australian research has found that popular fitness and supplement videos on TikTok can leave young men feeling worse about their fitness and nutrition, and increase their interest in using muscle‑building supplements.
The Flinders University study, published in the international journal Body Image, is one of the first to experimentally test the immediate impact of TikTok content on young men's body satisfaction and health intentions.
More than 280 men aged 17 to 30 were shown just three minutes of TikTok videos featuring either fitness advice, supplement promotion, or unrelated travel content, before reporting how they felt about their bodies, fitness, nutrition and intentions to use muscle‑building substances.
Those who viewed idealised fitness or supplement videos reported lower satisfaction with their fitness and nutrition than those who watched travel content, and they showed stronger intentions to use creatine, a popular muscle‑building supplement. Fitness‑focused videos had particularly strong effects, reducing fitness satisfaction and increasing supplement interest even more than supplement‑specific content.
Lead author and psychologist, Dr Nepheli Beos, says the findings show how quickly this type of content can influence young men's perceptions and behaviour.
"Just a few minutes of idealised fitness or supplement content can change how men feel about their own fitness and nutrition and increase their desire to seek products that promise faster muscle gains," says Dr Beos, who completed the research while undertaking her PhD at Flinders University.
Senior author and body image expert Professor Ivanka Prichard, says the research adds important nuance to what is already known about social media and male body image.
"It's not screen time that's the problem - it's repeated exposure to hyper‑muscular bodies, supplement promotions and steroid‑style fitness content, which is increasingly being linked to muscle dysmorphia, a diagnosable mental health condition," says Professor Prichard, who is also Director of the Embrace Impact Lab.
"We also found that workout advice can sometimes be more influential than straight supplement promotion, because it can make men feel they need extra products just to keep up."
The effects were strongest among men with a high drive for muscularity, who were more likely to feel dissatisfied with their nutrition and show interest in more extreme muscle‑building substances.
The study found that appearance comparison played a central role, with men who compared themselves to the bodies shown in the videos reporting poorer satisfaction and greater interest in supplements.
"Social comparison is a powerful but often overlooked driver of health behaviour, especially on highly visual platforms like TikTok," says Dr Beos.
"When you are directly comparing yourself to someone who is unrealistic or heavily idealised, the impact on your wellbeing can be significant."
The researchers stress that not all fitness content or supplement use is harmful, but say young men need better tools to critically assess online messages that often oversimplify benefits and downplay risks.
They say the findings highlight the need for targeted media literacy education and more responsible social media practices.
"TikTok's idealised fitness content doesn't just inspire exercise - it can actively undermine satisfaction and encourage substance use," adds Dr Beos.
"What looks like harmless fitness inspiration can quickly become pressure, comparison and risky behaviour, making it critical that young men are supported to navigate these platforms with a more critical eye."
The paper, 'The impact of fitness and supplement TikTok content on body, nutrition and fitness satisfaction, and intentions to use muscle-building substances in young men', by Nepheli Beos, Eva Kemps and Ivanka Prichard was published in Body Image. DOI: 10.1016/j.bodyim.2026.102082
See also, The dangerous pursuit of muscularity
