There's clearly a pretty big public health crisis when it comes to food. So saying "in moderation" is very hard to judge! Clearly the status quo isn't great.

So what's a moderate amount of fat to consume?

It could be half of what people tend to consume. it could be 10%. It could be double!

Given that if you follow "eat what you like" you end up in a bad place, it's kind of hard to lend credence to stuff like paleo.

So you're back to square 1 of having not much of a great idea. My bet is that the moderate amount of stuff that would be healthy vastly differs from what the "average minus 15%" or something would be.