Consider these questions: Why did we as a society collectively decide skinniness is a desirable trait? Why do we perceive others as “inferior” when they don’t fit into the standard we believe? And finally, why and how did these arbitrary standards even arise? If you couldn’t already tell, we enjoy probing the captivating word, why.
If you start asking (why, who, where, how), you'll find answers. And once you get those, you'll have the choice of believing those toxic standards or challenging them.