On the harm of "online" 👩‍💻👨‍💻

There is a good science fiction film with Bruce Willis (shot before the end of his career ) - Surrogates, about the future where people partly live "online" in a virtual world, while their bodies get fat and age somewhere in a dusty apartment. The film echoes the ideas of various science fiction writers Strugatsky, Lem, Lukyanenko. However, even these guys would be surprised to watch how we were all "digitized" during the times of covid restrictions. Study, work, communication, dating - all this has acquired a new fashionable format "online".
Perhaps some of you think that this is progress, but I will agree with the main character for whom what is happening in the plot was a dystopia. I will try to explain from the point of view of biology what will happen to us in the "online" world:

The online work/study format leads to a kind of social isolation, which in turn can lead to depression and other mental disorders due to a decrease in the nerve growth factor BDNF and the level of some neurotransmitters. To understand this, go to the zoo and compare the appearance of lonely animals and those in pairs/groups

The online format leads to a decrease in physical activity, hence problems with blood vessels, lymph drainage, and these are varicose veins, hemorrhoids, prostatitis and other nasty diseases that used to be only found in old people.

"Online" leads to persistent vitamin D deficiency.

Due to the above reasons, a person's immune system activity decreases ("stay home, stay safe" is a slogan for idiots)

Online leads to weight gain due to fat, since energy is not spent, and access to food is unlimited.

Guys who work online for a long time without "live" contact with girls experience a drop in testosterone levels and an increase in prolactin levels (I call this IT syndrome ). This is partly why "Tinder machos" may not understand how to behave with girls in real life. Similar processes also occur in girls who live on Instagram.