Ah sorry, I used source 1 from that article, this chart. Citing a second-hand source was sloppy of me.  Their next range is up to 24% for men and 31% for women, which they call "acceptable", not "average". This is only my opinion, but I think the difference between healthy and fit is muscle.  If you are healthy and not fit then you are lean.  Therefore, body fat is still an accurate representation of health.  But again, just my opinion. Anyway, I will try some different numbers in the spreadsheet and get back to you.