23-05-2025
Obesity by Stealth: Marketing Unhealthy Food to Teens
MÁLAGA, Spain — In 2020, Portuguese football star Cristiano Ronaldo made headlines off the pitch when, during a press conference, he pointedly removed two bottles of Coca-Cola placed in front of him and held up a bottle of water instead. 'Água,' he said. The clip went viral. It was a powerful example of how celebrity influence can shape health behaviors, offering a rare glimpse into the potential of using the same marketing machinery often employed to sell sugary drinks to instead promote healthier alternatives.
This anecdote raises the deeper issue of how digital marketing, particularly that targeting adolescents, is driving unhealthy dietary habits and contributing to the global burden of obesity and associated diseases.
Digital Marketing's Subtle Power
Gastón Ares, PhD, adjunct professor of sensometrics and consumer science at the University of the Republic in Montevideo, Uruguay, studies the intersection of food marketing and adolescent behavior. Speaking at the European Congress on Obesity (ECO) 2025, Ares outlined the insidious ways in which digital marketing has reshaped what young people eat, drink, and aspire to.
Gastón Ares, PhD
'Digital marketing is one of the key drivers of unhealthy diets during adolescence today,' he said. 'Adolescents are constantly exposed to messages — on Instagram, YouTube, TikTok — of people consuming fast food, soda, sweetened beverages. It's become a part of adolescent identity.'
Unlike earlier generations, which may have consumed soda or fast food occasionally, today's youth see it as a norm, reinforced by the persistent presence of these products in their digital lives. 'Twenty or 30 years ago, you drank soda once a week. Now it's a daily behavior. It's been normalized, and that normalization is part of who they are,' Ares explained.
Vulnerability Meets Persuasion
Adolescents are neurologically and emotionally primed to be influenced. They are undergoing rapid and profound biologic and social change. Adolescents crave social belonging, have reduced inhibitory control, and are particularly sensitive to rewards. These characteristics make adolescents particularly vulnerable during the 5-12 hours per day during which they are exposed to digital media.
'Influencers don't just promote products; they appeal to and shape social norms,' Ares said. 'Adolescents identify with them. They're aspirational figures. If your favorite YouTuber or TikToker is constantly holding a branded energy drink, or it pops up on their video, it becomes part of your world, too.'
In studies by Ares and others, 6-9 out of 10 adolescents recalled seeing at least one food or drink advertisement in the previous week, almost all of them for unhealthy products. Only a handful mentioned fruits or vegetables.
Ares also described recent research on self-reported exposure to digital food marketing and consumption frequency of ultraprocessed products. The data indicate a clear association between exposure to an advertisement in the week before the survey and consumption: Soft drink consumption increased by 53% and energy drink consumption by 114% after exposure.
Subtle and Subliminal
Unlike traditional ads, digital marketing is often subliminal. Some adolescents who have contributed to the research conducted by Ares report a creeping sense of 'harassment' by ubiquitous ads for unhealthy food.
'Even if they're not consciously aware, it sticks,' he said. 'They'll say they're not influenced but later admit they might choose a meal based on something they saw online.'
This type of advertising isn't just persuasive; it's personal. With targeting algorithms, companies deliver highly specific messages that resonate with individual preferences. It's cost-effective, far-reaching, and largely unregulated.
Marketing Promotes Overconsumption
Also at the ECO 2025 conference, Emma Boyland, PhD, chair of Food Marketing and Child Health at the University of Liverpool, Liverpool, England, presented findings from a randomized crossover trial of 7- to 15-year-olds. The research demonstrated the effects of food marketing across various media, including TV, social media, podcasts, and posters. It also examined the brands or products presented in this marketing. Five minutes of exposure to junk food ads was associated with children and adolescents consuming an extra 130 calories per day on average.
'This study is the first to demonstrate that brand-only food ads, for which there is currently no restrictive advertising policy globally, increase children's food intake. This new knowledge will help in the design of urgent restrictive food marketing policies that can protect children's health,' said Boyland.
'Our results also show that unhealthy food marketing leads to sustained increases in caloric intake in young people at a level sufficient to drive weight gain over time.'
Moreover, the study found that children with higher body mass index consumed even more calories post exposure, highlighting how marketing may disproportionately affect vulnerable groups.
Aspiring to Celebrity
In interviews with Ares, even adolescents who claimed immunity to food advertising acknowledged its power. 'One participant said, 'That's the closest I can be to a celebrity: By eating what they eat,'' Ares observed. He added that advertising worked at a subliminal and emotional level, even if the recipient believed they were unaffected by it.
Indeed, some adolescents support advertising when it evokes small businesses or local enterprises, suggesting that the perceived value or morality of the advertiser also plays a role in how marketing is received and rationalized.
Medication Messaging
Daisuke Hayashi, PhD, a graduate student at The Pennsylvania State University in University Park, Pennsylvania, has been studying food noise, which is defined as obsessive preoccupation with food and eating that often is associated with cue reactivity and disordered eating behaviors. At ECO 2025, he presented a new analysis revealing that around half of the 100 top TikTok videos under the hashtag #FoodNoise referred to the use of medications (primarily glucagon-like peptide 1 receptor agonists like semaglutide and tirzepatide) to manage persistent and intrusive food-related thoughts. This content, while potentially empowering for some, may also confuse younger viewers who could misinterpret normal hunger as a pathologic problem requiring drug treatment.
'TikTok can be an incredible tool for raising awareness, but it also has a downside,' Hayashi said. 'Many young viewers may not understand the difference between food noise and natural appetite.' The TikTok content studied had high viewership (averaging over 1.1 million views per video). About 71% of the content comprised patient testimonies, and 5% disclosed sponsorship.
'This [finding] raises ethical concerns,' Hayashi noted. 'Undisclosed promotion could lead to unintentional harm, especially among adolescents forming their food identities.'
Given that TikTok has more than 1 billion users, most of them young, the findings underscored the urgent need for digital literacy and stricter advertising transparency as conversations about weight-loss medications and body image proliferate.
Same Tools, Different Purpose
Medscape Medical News asked Ares whether similar strategies could be deployed to promote healthy eating.
'Yes, but the challenge is funding,' he replied. 'Governments often focus health messages on rational benefits, including long-term health and disease prevention. But junk food marketing appeals to pleasure, fun, and identity. That's what we need to do, too.'
He points to Ronaldo's rejection of Coca-Cola as a rare but effective example: A health-positive message delivered by a globally admired celebrity and focused on strength and clarity, not guilt or restriction.
'It's about using the same playbook. Bring out water at kids' parties. Make fruit part of the fun. Link health to belonging and aspiration,' he said.
New National Policies
Encouragingly, the United Kingdom is set to introduce legislation restricting the advertising of less healthy food in October 2025. Under the Health and Care Act 2022, new regulations will impose 'a 9 PM watershed restriction' on television ads for unhealthy foods and impose a 24-hour ban on paid online ads, including influencer content.
'This is one of the strongest pieces of marketing regulation globally,' Ares said. 'But there are loopholes. Brand-only marketing [which does not mention products] is still permitted.'
Meanwhile, Australia is planning to take the more radical step of banning children under 16 from having social media accounts. This step is designed in part to curb exposure to digital marketing.
'These are steps in the right direction,' said Ares. 'We'll need to see how they play out in practice, but they show political will.'
Global Action
Other countries are watching closely. Norway, for example, began drafting strong policies on targeted food marketing but reportedly softened them due to industry pressure. This development underscores a persistent challenge: The food and tech industries are powerful and well-funded.
'We're up against giants,' Ares said. 'Public health campaigns are underfunded, often reactive, and lack the emotional punch of commercial marketing. We need better budgets, more creativity, and stronger regulation.'
New Messages
To shift adolescent behavior toward food might require matching the emotional, social, and cultural weight of the messages that youth already receive.
'It's not just about facts, it's about identity,' Ares stressed. 'Marketing doesn't just sell products. It sells norms. If we want young people to eat better, we need to change what feels normal.'
And that may start with something as simple and powerful as a bottle of water lifted in front of a camera by someone young people admire.
