The forkandwait/ ancient Greek ideal diet: A bunch of whole grain bread, fish, olive oil, and all the random seasonal fruits and vegetables you can get your hands on, but don't eat until you are full. Every once in a while gorge on meat and dairy and honey. Get lots of exercise. Don't get killed in battle, get enslaved, or die in an epidemic.
There should be a special name and place in hell for all the diet bullshit that goes through the culture like this.
Not that i follow my own advice or anything...