The AI fitness instructors selling unreal gains

The videos promise users they can change their bodies in weeks, "look 20 years younger", or "lose 40lb in one month". Once users engage with exercise or fitness content, algorithms quickly flood their feeds with similar material. Prof Andy Miah, an AI expert from the University of Salford, says the trend is "huge" and those scrolling are drawn in because they are looking for advice.

"People are looking for solutions to their health, their fitness, their looks," he says. "There's always been an appetite for that kind of content - but now it's incredibly hard to tell who to believe. " Unlike human influencers, AI characters can produce content endlessly, and users cannot opt out.

"You can't turn [AI content] off," Prof Miah says. "It's impossible to stop your feeds being proliferated with this material. " He accepts there are many positive aspects to AI, but describes the current landscape as a "wild west" in terms of regulation and says some ads could be harmful.

"The claims about how quickly you can make gains are completely unrealistic," he says. "That feeds false hope and creates damaging expectations. " The BBC contacted the companies behind several of the adverts found to be problematic.