For men, yes. For women, no.
Men have about 3 to 4% essential body fat, which is the fat found in your nerves, brain, and internal organs. This fat serves essential functions in the body (hence the name), so it’s never broken down for energy the way other body fat is. In other words, you would starve to death before your body began breaking down essential body fat.
Women have more essential body fat than men—about 8 to 12%. Thus, women can’t achieve 5% body fat.
The bottom line is that the absolute leanest a man can get is about 4 to 5% body fat, and the leanest a woman can get is about 8 to 10% body fat.