Eating all day and night causes our pancreas to constantly pump out insulin. Not only do most people eat all day, they also eat highly processed foods, carbs and sugars that are easily digested (they have a high Glycemic Index). Visceral fat is technically excess intra-abdominal adipose tissue accumulation. It's also known as a “deep” fat that is stored further underneath the skin than “subcutaneous” belly fat. It's a form of gel-like fat that's wrapped around major organs, including the liver, pancreas and kidneys.
Many studies have pointed to an association between insulin resistance and visceral fat. resulting in the increased risk of a number of health problems including type 2 diabetes. Visceral fat secretes a protein called retinol-binding protein 4 (RBP4) which has been shown to increase resistance to insulin.