[Sharlin]

I wasn’t aware of the degree of disparity in early-onset ischemic heart disease, thanks. But it doesn’t seem to me it’s "mostly heart disease rather than risky behavior", more like those are both major causes of excess mortality among young men.

[somenameforme]

As a related topic, sex ratios [1] are extremely interesting to look at, as well as consider the overall effects (and evolutionary history) of. Most people think the chances of a child being male or female is 50/50. It's not! A newborn is somewhere around 5-7% more likely to be male than female. In times past this would level out extremely rapidly to the point that by our thirties, the sex ratios was more women than men.

But in modern times it's persisting much longer such that in our twenties there are still about 6% more males than females. Consequently, and in terms of actual coupling, this now means that even if every single female was actively seeking a partner, about 6% of men would end up alone. Homosexuality and other features may change the ratios somewhat, but it's probably again a fairly reasonable ballpark.

[1] - https://ourworldindata.org/grapher/sex-ratio-by-age