Does straight media (ie media that emphasizes sexual attractiveness) show thinner women?
Straight media places a very high importance on how "good" (be that against whatever metric) a woman looks, with lesser (but growing) equivalent importance on men looking good.
I think the high rates of body dysmorphia and mental illness amongst gay males are more likely caused by homophobia. If you're constantly told that you're lesser, chances are great that it will affect your self esteem.
I'm not talking about mental illness in general - I'm talking about body dysmorphia and eating disorders specifically.
Sure, other depression- and anxiety-based mental disorders in gay men are highly likely to be linked to homophobia and other negative influences in people's lives.
Gay people aren't a monolithic bloc and if you want evidence that there are plenty of gay men who find chubby guys attractive, all you need to do is go back a page or two in this thread.
It's not necessarily about a specific bodily ideal than it is about the importance placed on body image generally. In that sense, I'm reminded of that "gay cliques census" (that people here often run through) that, based on five variables, will put you into no less than one of 17 categories of body image. Where is the straight male's equivalent?
However, I'd also be prepared to argue that there is a homogeneity to body types generally presented in gay media, in the same way that there is a homogeneity to body types in media targeted at women.
(Edit: I also find the idea the argument that "gay people aren't a monolithic block" pretty disingenuous. Of course not every gay person thinks the same way, but that doesn't mean that certain issues arrive from how their actions and/or preferences might be construed overall. Similarly, I'm not looking to disrepute the suggestion that
some gay guys find "chubby" men attractive, but that, given the literature which suggests so, gay men may be more likely to suffer from body image problems than their straight counterparts.)
(Edit2: In the interest of neutrality, I think it fair to mention that I have also come across studies which suggest that exposure to gay media specifically
doesn't lead to an increase in body dysmorphia among gay men. Nevertheless, the studies that I have read have overall suggested that correlation.)