If anything, I've seen far more "positive" fat woman characters than male.

Yeah, homer simpson and peter griffin are fat stupid idiots, and yet they somehow manage to land their smart attractive wives without effort.
Its entirely possible to accept the premise that womens portrayal in mass media is based more on looking attractive and that men often aren't held to meeting those same standards, but also accept that its possible to take that premise way too far and ignore medical realities.
Its also fine to question the premise that it is cishet men responsible for that same media portrayal, as certain feminist theories assume; if you look at media
specifically designed for the male gaze - porn - women tend to be shorter and curvier than 'mainstream' media portray them. Media aimed specifically at women, such as fashion magazines, promote a 'size sero', taller, flatter, thinner, more androgyne look, that a lot of women just genetically can't meet.
e: same deal with the whoreswhoreswhores thread on era; its mostly dudes. Its mostly
gay dudes. Its mostly pushing an androgynous look as being 'acceptable' for women, because they like twinks and not female porn stars.