Normal men 14- 17% athletes are mostly around 10%, and bodybuilders or other athletes can be as low as 4% in the season. But for ordinary people, I think it is healthier to keep 14- 15% or so, because athletes can keep competitive all the time in a superior nutritional environment for the sake of competition results. For ordinary people, it is good to have loose bowels, stay up late, go on business trips and save some fat.