People living with diabetes report that they are stigmatised and blamed for their condition, and that media are a primary source of stigmatic representations. Our analysis found that, consistent with the notion of diabetes as stigmatised, use of the hashtag #DiabetesOnAPlate on Instagram, was associated with indulgent eating and with posts that signalled recognition of this as a moral transgression. A subsequent on-line survey found that participants who did not have diabetes did not recognise a prototypical #DiabetesOnAPlate post as stigmatic. Whilst some of those with Type 1 and Type 2 diabetes did perceive and contest the stigma, Type 1 participants did so for their group (but not for Type 2); and there was evidence that some Type 2 participants internalised the stigma. These findings support concerns about the everyday, divisive nature of stigmatic representations of diabetes on social network sites, which may compromise health messaging and positive health behaviours.