A study from the University of Pittsburgh shows that the marked increase in diabetes in older people is caused by obesity and lack of exercise, not by aging alone ( Diabetes Care, August 2009). Most cases of diabetes are caused by cells not being able to respond to insulin, rather than by lack of insulin. Inability to respond adequately to insulin is caused by being overweight, not exercising, lacking vitamin D and/or eating too many refined carbohydrates.
In this study, the same insulin responses were found in young and old endurance-trained athletes, young and old normal-weight subjects, and young and old obese subjects. Regardless of age, athletes had better insulin responses than normal-weight sedentary subjects, who had better insulin responses than overweight people.
If you are overweight, try to lose the extra weight. Check with your doctor and start or continue an exercise program. Get a blood test called vitamin D3. If it is below 75 nmol/L, you need more sunlight or vitamin D pills. When you are not exercising, avoid sugar water and flour. More on diabetes prevention and treatment