Calorie counting app creators have been criticised for allowing the platforms to be misused by people with eating disorders.
The BBC found content logging self-harm and punishments for over-eating on MyFitnessPal, Lose It! and Lifesum.
Eating disorder charity Beat said the mobile apps could exacerbate unhealthy behaviours and make recovery harder.
The app developers said they promoted healthy eating, and safeguards to protect vulnerable users were in place.
An investigation by the BBC found more than 20 harmful entries generated by users of MyFitnessPal, Lose It! or Lifesum, including some promoting dangerous cycles of starving and binging.
https://www.bbc.com/news/uk-england-birmingham-48842898