TV chef Jamie Oliver has said he has banned his 14-year-old daughter from sharing selfies, describing them as the unhealthy "sugar of social media".
"We ban Daisy from doing selfies and mainly she doesn't, but a couple slip up," the father-of-five told the Lifestyle News Hound podcast.
Oliver, 42, says he is among the first generation of parents learning to deal with children sharing photos online.
He and wife Jools regularly post family photos on their own Instagram pages.
But Oliver, a prominent campaigner for healthy eating, described teenage girls' use of Instagram as "frightening".
He said: "I'm going to generalise massively here, but from my observation so far, at 13 to 14, the kind of pictures that girls are putting up, just from what I've seen, split off 50:50.
"[There's] normal young girl, and then this weird hybrid of - dare I say it - quite porno sort of luscious kind of pouty lips, sort of pushing boobs out."
He said he did not "even want to look" at photos of other girls that 14-year-old Daisy had shown him.
"I'm like really? Are their parents not over that like a rash?"
However, Jamie and Jools Oliver are not against Instagram itself - and frequently post snaps of family holidays and days out that they are happy to share with the public.
Oliver added: "Because of the 'like' thing, it's kind of almost the sugar of social media.
"It's a quick way to get some kind of pat on the back or love."
The NSPCC charity has told parents it is vital to spot inappropriate behaviour online - and has a Net Aware guide to social media sites young people are using.
The charity identified a number of risks for children using Instagram, including strangers following them and people taking screenshots and sharing photos without their permission.