Grandma and Great Grandma always knew this. (both lived to over 90)
Most of these "health" and "food" things come from bureaucrats and interest groups, not doctors. I don't pay much attention to the fad food fake panics in the first place, simply because they just don't make sense.
That said, everything in moderation. We are omnivores and should intake accordingly, it's genetic, and if one skews to one side or the other still do that in moderation just to keep the bones strong and the heart healthy. And put down that cell phone, get up from behind the keyboard, and exercise, preferably in the great outdoors, or at least on the front stoop.
I used to take these studies seriously - I was a serious fella when young - until a study was published (early 1970s) claiming too much sex was bad for one. Ever since I've been trying to prove the study correct...