avani: lauren hemmings is studying to be a midwife. boredom that kind of motivated me to download it. it was quite an innocent hope of just getting a good laugh, really, you know, like getting funny vide and seeing what was on it. i never had the intention of making tiktoks or sharing them. it was more just kind of from the viewpoinof, yeah, the viewer. avani: lauren started following a popular fitness influencer on the app. lauren: there's one woman who had, like, quite a simir body type to me. and she'd expressed that she was unhappy with that body type. and she had started tracking calories over quarantine. she had lost a really, really significant amount of weight. avani: the algorithm then flooded her feed with content promoting unhealthy weight loss. lauren: i was no longer seeing funny dance videos or anything. it was just like this completeocus on that, like, fitness and healthy lifestyle goal. avani: tiktok pushed lauren toward the popular trend of meticulously tracking how many calories you eat in a day. something researchers