3. Diets low in fiber are directly correlated to heart disease, fat retention and colon cancer. It also makes the process of passing stools more difficult which can leave stools in the system for longer than is normal. This means the toxins in your body cannot leave fast enough and some of it is absorbed back into the body. Higher toxins in the body makes the liver work harder which makes it harder to lose weight. High visceral fat is a sign a man has low testosterone.