Like sexism, it elevates the status of one group of people at the expense of another. Women, more often than men, are the victims of size discrimination in employment, education, and adoption. Fat women also suffer more social discrimination based on size. Consequently, we try to achieve an unrealistic body size by dieting, surgery or drugs. But there are other options.
Humans come in all sizes.
When we reclaim the right to eat, focus on our lives and stop giving our money to the diet industry, anything is possible. The first romance novels written about generously proportioned women. Weight prejudice is a true form of bigotry in every sense of the word. Like anti-Semitism, it defines an entire group of people numbering in the millions within a narrow range of negative characteristics and behaviors. Like sexism, it elevates the status of one group of people at the expense of another.