Maintaining physical and mental performance with a revolutionary diet that helps prevent age-related diseases. Sears explains that it is possible to reverse our `biological' age (which is different to our `chronological' age) if we look at our hormones and our diet. It is crucial to maintain the right balance of hormones in our bodies - ageing is not necessarily about the decreasing of certain hormones but rather how they effectively communicate with each other to maintain equilibrium. The Zone is a revolutionary diet plan which advocates a lower intake of carbohydrates which convert to sugar creating a diabetic-like condition. If we eat more protein and monosaturate fats we enter the Zone of optimum metabolic function. This diet has been proven in preventing age-related diseases: heart disease and diabetes (non-insulin dependent diabetes largely occurs in older age). Sears explores the activity of hormones as we age and gives a dietary plan (and supplement advice) to maintain peak performance: * calorie restriction without hunger or deprivation * insulin, cortisol, seratonin and eicosanoids * oestrogen and the menopause * testosterone as men and women age * DHEA, melatonin - are these hormonal supplements merely hype? * your thyroid gland and how it affects metabolism * exercise and the anti-ageing Zone lifestyle `pyramid'