Scroll through TikTok or Instagram for five minutes and there’s a good chance a creator will explain exactly what to eat to look the way they do. A flat stomach. Toned arms. That “glowy” skin. The pitch always sounds simple: copy the creator’s diet, get the creator’s body.
New research suggests that pitch is not only oversimplified but often flat-out wrong, and that it tends to come from people with no business dispensing health advice. A team of Australian researchers, writing in the Journal of Technology in Behavioral Science, analyzed 300 videos tagged with popular healthy-eating hashtags on TikTok and Instagram and found that more than two-thirds contained misleading or deceptive information. Most of that content came from influencers with no dietitian training, nutrition degree, or health credential of any kind, while the small slice of videos made by actual qualified professionals, like dietitians, was far more likely to be accurate.
Researchers weren’t just counting up bad advice for its own sake. They were hunting for patterns connected to orthorexia nervosa, a condition marked by an unhealthy obsession with eating only foods considered “pure” or “clean,” rigid food rules, and distress when those rules are broken. What they found describes a social media world filled with many of the same themes tied to that kind of thinking, hashtag by hashtag, whether the person posting means to or not.
Inside the TikTok and Instagram Diet Advice Study
A research team from Flinders University in Australia searched TikTok and Instagram for the hashtags #healthylifestyle, #nutrition, and #cleaneating between May 25 and 27, 2025. For each hashtag on each platform, they pulled the first 50 videos that came up, skipping duplicates, which added up to 300 total videos: 150 from TikTok and 150 from Instagram Reels. Videos ran about 26 seconds on average on both platforms, so length wasn’t a factor separating the two.
Women were the focus for a reason. They make up a large share of the user base on both apps and face a higher risk of eating disorders, so the researchers zeroed in on content aimed at and featuring women.
Researchers coded all 300 videos against a detailed checklist built to capture signs linked to orthorexia: things like moral language around food (“good” versus “bad” foods), body-focused messaging, restrictive eating rules, exercise habits, and whether the information shared was accurate. Creators were then looked up on Google or LinkedIn to check whether they held any real qualification in nutrition, dietetics, or exercise science, a detail kept hidden during the initial coding so it wouldn’t sway the ratings. To confirm the scoring held up, a second reviewer independently coded a fifth of the videos, and agreement between the two came out very high.
What the Videos Actually Showed
Food and people appeared together in nearly three out of four videos, a format that visually ties eating habits directly to how someone looks. About 36% of videos pushed a specific eating pattern, and 67% emphasized “clean” or “healthy” eating as a core message. Supplements or so-called superfoods showed up in about 75% of videos, and roughly half turned healthy eating into a kind of lifestyle trend, presenting food more like a brand than something to actually eat.
Nearly one in three videos imposed actual food rules or restrictions, telling viewers to hit specific protein targets, cut out entire food groups, or follow rigid patterns like always pairing dinner with a protein source. Moralizing language, the kind that frames food choices as reflections of a person’s character or worth, showed up in about 20% of videos. One creator in the study put it directly: “I eat high-quality foods because I’m a high-quality person.”
Body objectification appeared in 63% of all videos studied, but Instagram was noticeably more intense on this front, hitting 78% compared with 48% on TikTok. Instagram also zoomed in on specific body parts more often and was far more likely to show people with lean, muscular bodies, 70.7% of the time versus 47.3% on TikTok. On Instagram, about one in three videos had creators directly crediting their physique to a specific diet choice, compared with 16% on TikTok. Exercise followed a similar split: Instagram leaned toward strength training and framed workouts around appearance more often, while TikTok leaned toward cardio and framed health in more general wellness terms. Across both platforms, roughly 10% of videos showed exercise that was compensatory or excessive.
Who’s Really Giving the Diet Advice
Perhaps the most telling numbers in the study concern who’s doing the talking. Unqualified influencers made up the vast majority of creators in the sample, a status verified by checking public bios and LinkedIn profiles.
That imbalance mattered for accuracy. Across the full sample, 68% of nutrition and exercise information was rated misleading or deceitful. Qualified creators were far more trustworthy: 45.5% of their content was rated accurate, compared with just 4.7% of content from unqualified influencers. Unqualified influencers were also far more likely to post content rated as misleading, 75.2% versus 40.9% for qualified creators, or outright harmful. One example flagged as harmful showed a creator eating a tiny portion of food captioned “I am so proud of myself when I control what I eat.” Another video, titled “How I lost 2kgs in 7 days,” featured a food diary consisting mostly of liquids and portions as small as one date and eight slices of cucumber for an entire lunch.
Qualified creators, meanwhile, were more likely to post under the straightforward #nutrition hashtag rather than the more lifestyle-branded #healthylifestyle or #cleaneating tags. That means the people best equipped to give sound advice were the least visible under the hashtags most associated with idealized, aesthetic content.
Source: https://studyfinds.com/nearly-70-of-diet-advice-on-tiktok-and-instagram-is-misleading/
