They say that our society eats junk and fast food and all that crap and that ancient people ate fresh fruits and nutritious stuff.

But ancient people seem like they died earlier. If I'm not wrong, I've heard stuff like they had a life expectancy of 30 or something.

They did not have the medical advances we have today.

I think it is because we have good healthcare,hygene etc.We also sleep in warm, comfortable beds, have adequate heating, tend to afford warmer clothes and rest more. We can import a variety of food items also.