Technically there shouldn’t be anything wrong with being fat. The only other problem is that people don’t recognise that it’s possible to be both healthy and fat, if the likes of sumo wrestlers, some weightlifters/powerlifters and Butterbean are any indication though it could be that they exercise fairly often to keep it at acceptable levels. (Whatever fat they restore’s often right underneath the skin instead of inside the body.)
It also gets complicated by that women tend to store more fat than men do. Even somebody like Kate Moss’s going to be technically fatter than Hedi Slimane. It’s possible for them to put on muscle though it’s usually going to be either harder or less obvious for them. Not that we should discourage women from exercising and growing numbers of them are doing it. Nor should we discourage them from not fitting in either.
It’s possible to be both fat and healthy for as long as you exercise (and eat right), it’s alright.