You're right, fast food is probably not the primary offender, and there are many causes (HFCS, seed oils, not cooking, abundance in general), and future is overdetermined... but fast food definitely carries some responsibility for the obesity epidemic.

Same with porn and Pornhub. But it is the mental tobacco of our time.

> mental tobacco [of] our time

You may want to check how early does porn (or sexualised images) exist. "our time" may turn out to be "since we discovered drawing".

You should check your history. Tobacco was native to South America and introduced to the rest of the world in the 1500s. You could argue it is prehistoric to South America, but that is very different from "barely more recent than drawing."

Hemp smoking, on the other hand, has been traced back to many prehistoric sites in asia and africa which would fit your description much better.

What was your intended meaning for "of our time" in that case?

It was in relation to widespread use and availability of pornography, like tobacco was in the 20th century. Or like obesity is now.

We had obese people since at least the first settled societies. But it was nothing like today, both in how widespread and how extreme is has become.

Same with drugs. An opioid epidemic pushed by mega pharma is nothing like a shaman serving ayahuasca.

A nude cave painting or a figurine is nothing like thousands of hours of streaming porn. Barely related.