A fascinating review from Tufts University in Boston shows how excess fat stored in muscles causes diabetes ( American Journal of Clinical Nutrition , March 2007). Before insulin can do its job of driving sugar into cells, it must first attach on special hooks on the surface of cell membranes called insulin receptors. When excess fat is stored in muscles, the insulin receptors internalize so that insulin cannot attach on the hooks. This markedly increases the amount of insulin that is necessary to drive sugar into cells, and eventually huge amounts of sugar accumulate in the bloodstream to cause diabetes and damage every cell in the body.
Excess deposition of fat into muscles is caused by eating to many calories, not getting enough exercise and eating too much saturated and partially hydrogenated fats. Most cases of Type II diabetes are caused by a faulty lifestyle, not genetics, and are both preventable and curable with proper exercise and diet.
You can tell if you are at high risk for diabetes if you store fat primarily in your belly. Pinch your belly; if you can pinch an inch, you are at increased risk and should get a blood test called HBA1C. Having high blood levels of triglycerides and low levels of the good HDL cholesterol that helps prevent heart attacks also increases your risk for diabetes. When you eat sugar or flour, your blood sugar rises too high. This causes your pancreas to release insulin that converts sugar to triglycerides, which are poured into your bloodstream. Then the good HDL cholesterol tries to remove triglycerides by carrying them back into the liver, so having high blood levels of triglycerides and low blood levels of the good HDL cholesterol are both individual risk factors for diabetes.
High blood levels of insulin constrict arteries to raise blood pressure, so many people who have high blood pressure are also prediabetic. High insulin levels also constrict the arteries leading to your heart to cause heart attacks directly. People with insulin resistance have an increase in small, dense, low-density lipoprotein (LDL) cholesterol, which is more likely to cause heart attacks than the large, buoyant regular LDL cholesterol. High levels of insulin also cause clotting to increase your risk for heart attacks. You can help to prevent diabetes and heart attacks by avoiding sugar and flour, exercising and eating lots of vegetables. More on insulin resistance