Yes and no, some fat is more expendable than other fat. Anyone who dieted in the single digits knows that you have to sacrifice muscle to get there, and that's nowhere the level of depleting all vital fat stores. Even with tremendous drug abuse bodybuilders struggle to reach dangerously low bodyfat.  I can see some anorexics being skinny-fat, depending on how you define it. Some vegans are anorexic and vegans are almost always skinny-fat due to malnourishment. But skinny-fat isn't the same thing as being fat. What makes skinny-fat people look so bad is the softness/sagginess of their physique rather than the sheer amount of fat they carry.