Millennials are having less sex than any generation in 60 years

* Insane portion sizes when I eat out.

* If there is a smaller size it feels not worth it (it's not that much smaller, but the cost is still dis-proportionately high, adding a psychological barrier to ordering less)

* I hate leftovers, but I was also given that 'starving children in Africa' speech as a kid... I hate leaving food behind.

* I have a 'desk job' and thus don't get enough exercise.

* American culture is predominantly a car culture, our cities, suburbs, and rural areas are built to that standard.

* I wasn't, really, at all trained in making HEALTHY food as a kid.

* Making healthy food takes some time, or at least a good bit of planning.

* Making food for one means I can't keep the best healthy ingredients around. (Fruits, vegetables, to a degree bread) Even the smaller store sizes are at high risk of going bad before I get them, and they have a cost high enough to make me lust for prepared foods.

* Most of the prepared foods are made to sell on taste, and thus have a lot of what isn't 'healthy' for us.

* We've also, apparently, been on a war against fats, when their common substitute sugar is actually a more insidious enemy.

In the surveys I've seen before, the average number of reported female sexual partners per man did not equal the average number of reported male sexual partners per woman. Men overreport their number of sexual partners; women underreport. This effect could skew the aggregate reported results among the entire population one way or another, depending on other factors.

If the underlying trend is one of increasing inequality in male sexual activity -- fewer men having sex with more women, while women have the same number of sexual encounters overall -- then because fewer men have had sex, the proportion of all people who have never had sex would increase compared to previous generations, even if the average amount of sex across the board actually remained the same as in previous generations.

Moreover the societal group ties have disappeared. You can see it as many fewer subcultures and subgroups. Quite a few are virtual (Internet based, not local) and that does not lens itself to relationships. Results in loneliness in crowd, since everyone is a stranger.

To C: Probably people know more about sex than they used to, not less. Anyway sexual eduction leads to the first sex you have being later in life.

Porn certainly is more accessible and widespread than it has been.