As stated in my last post, there are indeed some slim people in FatLand. As FatLand develops its own complex growth and weight curve, they don't stand out quite as much as they used to.
However, in the earlier years of FatLand, there were very few slimmer people. And they did stand out markedly. They were sometimes ridiculed and sometimes harassed. They had extreme difficulty finding clothes. They also experienced problems on FatLand public transport, which was designed for heavier people.
After the killing of a beautiful fat Egyptian dancer and the involvement of a slim child of Board members in an attempt to undermine FatLand (after which she reversed her views and became a shero on the Fat Underground Railroad), the FatLand Board realized that they had to make sure that education and consciousness raising about universal Size Acceptance would be provided for children and adults. This effort did help, and in subsequent years FatLanders actually had some children who werer naturally slimmer and also those who grew up not having to diet. By this time, Size Acceptance in FatLand was pretty much a given, and there were now no incidents of slim-shaming.