This is just an indicative idea of the dedication that it actually requires to reach those levels of body fat.  The person who wrote it absolutely DOES know what they are talking about.  Most people in this thread are grossly misrepresenting the slide as it was posted by a fat asshole to try and support their position. What is listed as unhealthy is less than 6% BF for men and less than 16% for women and SHOCKER that low body fat IS unhealthy and unsustainable.