Reddit's Pro-Eating-Disorder Communities and Documented Harm
2018–2021
Reddit hosted active pro-eating-disorder communities such as r/proED; a peer-reviewed longitudinal study using Reddit data found measurable real-world weight loss and shrinking weight goals among participants.
What happened
For years Reddit hosted pro-eating-disorder ('pro-ana'/'pro-mia') communities where members shared 'thinspiration,' fasting techniques, and encouragement to continue disordered behaviors. Around 2018 Reddit removed two of its largest eating-disorder subreddits for 'encouraging physical harm,' prompting a user petition to restore them.
Unusually for this kind of claim, the harm has peer-reviewed empirical support drawn directly from Reddit. A longitudinal observational study published in the Journal of Medical Internet Research (October 2021) analyzed user-generated data from the r/proED community and found that participation was associated with real-world weight loss (about 0.087 BMI points per week) and with users lowering their already unrealistic desired-weight goals over time, with more active members showing larger effects.
The causal language matters: the study documents association between participation and measurable outcomes within an observational design rather than a controlled experiment, but it is among the strongest evidence tying a specific Reddit community to offline physical harm. Broader research notes that bans can fragment such communities or push them to coded language and other platforms rather than ending the behavior.
Impact
Reddit removed several large pro-ED subreddits, and the JMIR findings have been widely cited as evidence that pro-ED communities are associated with worsening real-world health metrics. The episode informs ongoing debate over whether moderation, coded-term filters, or directing users to crisis resources is most effective.