If you're not a vegetarian, you can incorporate poultry, fish, and lean cuts of beef into your Zone meals. Hormonally, you're only as good as your last meal, and hormonally you're only as good as your next meal. Therefore, the balance of protein to carbohydrate at each meal will determine both your insulin and glucagon levels for the next four to six hours. Eat too many carbohydrates and not enough protein at a meal, and insulin levels will increase too much. Eat too few carbohydrates and too much protein at a meal, and your insulin levels will be too depressed.
Excess insulin is the primary accelerator of the aging process.
It is also the primary risk factor associated with increased cardiovascular disease. Many of the physical signs of aging, such as sagging skin, obesity, decreased strength, decreased mental focus, and increased risk of chronic disease, are directly or indirectly related to increased insulin levels. Of course, without enough insulin, your cells would starve to death, because insulin drives nutrients into cells. Until recently there were no good data to answer that question. Now recent long-term studies have demonstrated that excess insulin levels precede the development of obesity.