" To make matters worse, as you get older, your cells gradually become less sensitive to insulin's effects, so insulin levels must rise even more to produce the same results. This leads to a state of insulin resistance, which leads to even more insulin production. Over time, these increasing insulin levels, especially when combined with a poor diet, promote the weight gain and increase in body fat so typical of the aging process.
It's not a pretty picture, but this deterioration is far from inevitable. Commonsense lifestyle changes can help you keep your insulin levels under control: Following the major themes of our TRANSCEND program will help you keep your insulin at low, youthful levels. Maintaining a regular vigorous exercise routine burns blood sugar and drives it into your muscle cells, decreasing your body's need for insulin. Following our recommendations for a low-sugar, low-glycemic-load diet will lower insulin levels further. Finally, controlling your stress will lower your cortisol level and avoid the vicious cycle of cortisol-raising insulin. "

― Ray Kurzweil , Transcend: Nine Steps to Living Well Forever