Cannibalism is so rare that Wikipedia's category of American cannibals includes only 20 entries. And yet by looking at which groups are over-represented, we can learn something about which ones are likely to be so seriously screwed up that they would eat human flesh.
Some of them were high on drugs like PCP, and it's not clear they intended to eat what they ate. A handful of others were Mountain Men who ate parts of their enemies, as a form of over-kill or disrespecting them even when they were dead. And a couple were curious anthropologist types who wanted to "go native" for a bit.
I'm interested in the ones who were drawn to it per se, in order to make sure we're looking at profound psychopathology and not the other weird but non-pathological causes.
That leaves just 9 cases: Bar-Jonah, Dahmer, Fish, Toole, Chase, Cole, Kemper, Gaskins, and the Ripper Crew. All cases are male (no surprise there, as male biology is more unstable). Of the cases, 4 are homosexual (the first four listed) and 5 are heterosexual. The Ripper Crew was made up of 4 individuals, although it's unclear how many of them ate the flesh of their victims. At the level of individuals, then, between 5 and 8 are straight cannibals, and 4 are gay.
The prevalence of homosexuals in the male population overall is about 4 in 100, while among disturbed cannibals they are around 4 in 10 -- over-represented by an order of magnitude. Even though our sample is small, there ought to be 0 homos if they are no more or less likely to be drawn to cannibalism than normal males.
Why are gay men less repulsed by an act that most cultures view as a disgusting taboo? I think it stems from their fundamental trait, which is being psychologically stunted in early childhood ("girls are yucky"). At that age, not all taboo behaviors have had the time to root themselves in the "ewww, disgusting" part of the brain. Infants put all kinds of sick crap in their hands and mouths as they probe their environment, and hardened disgust reflexes aren't in place until later childhood and early adolescence.
Queers are way more likely to play with piss and shit, for example, as though they never grew out of being 5 year-olds. Human flesh would then just be a special case of their broader undeveloped sense of disgust and taboo.
Of course, to reveal this tendency of theirs would require them to murder somebody, in cold blood, and not as revenge but because they enjoy it per se. That restricts the sample (gay or straight) to serial killer types. So, we will not easily observe the lower threshold that homos have for eating human flesh, because it only takes place in such infrequent contexts. But when those conditions are met -- when we look for serial killer type behavior -- then the higher level of gay depravity exposes itself.
Related: queers over-represented among serial killers by 2 to 7 times.