I think one of the most attractive features of the zone diet to people interested in longevity is its low calorie intake. In a normal individual around 80% of the body's free radicals are produced converting calories into ATP to use for energy or store as body fat. The more calories you consume the more free radicals your body produces. I have an old dog eared copy of Maximum Life Span by the longevity expert Roy Walford. He was recommending a diet involving calorie restriction in 1983. Being one of the few brave souls who tried that diet and experimented with calorie restriction I can tell you it's no picnic (literally). The zone diet on the other hand is a practical method of calorie restriction with excellent nutrition and excellent hunger control. A wonderful breakthrough in the longevity field. For Longevity Other important areas not covered in Dr Sears book the Age Free Zone that really deserve mention are advanced hygiene and emotional health. For some reason which escapes me advanced hygiene has been almost completely ignored. Correct hygiene can reduce your incidence of colds and viruses significantly (in most people by up to 90%). Since viruses inhibit the production of good eicosanoids this is significant. Advanced hygiene has many other benefits related to longevity too lengthy to go into here. Worth thinking about. Kindest regards, Andrew Cavanagh