Sally Kohn: The concrete external harms of anti-fatness are often reframed and reinterpreted as insecurity by thinner people, especially women. She says skinny shaming is designed to sort of derail all of anti- fat bias into the idea that an individual person is being mean to an individual fat person. Kohn: As body positivity has become mainstreamed there is now this sense of ownership that thin women have over body positive spaces.