A key point to note from that Leigh Peele article:
"There is currently no definitive answer for what is essential body fat. Looking at research though we assume a range of 5% for men and 12% for women is landing in the essential range. For hormonal and reproductive reasons women need to store a higher level of body fat than men. It is thought that 15% is the lowest range a women should maintain. There is some argument about this, but technically the data isnít there to conclude if it is body fat or lifestyle/training habits that cause problem. In my personal opinion, I think women should tread lightly trying to maintain body fat levels below 15%."