On many social media sites, messaging about food and diet is everywhere. Watch the “for you” feed on TikTok for more than a few minutes – the recommended content for a given user of the app – and you are almost guaranteed to see a video in which someone shows you #whatieatinaday (#wieiad for short), or explains how their diet has transformed their body.

There is growing evidence that this can impact people’s body image, especially among teenage girls, which could lead to conditions like anorexia or…