This section of the book is from the "How and When to Be Your Own Doctor" book, by Dr. Isabelle A. Moser with Steve Solomon, published in 1997.
Some people not only want to be healthy, but they want to live in good health long past the normal life span projected by statistical tables for Homo Sapiens. Dr. Roy Walford, a well-respected medical research gerontologist who has been actively studying longevity for many years, is one of those. He has scientifically demonstrated with accepted studies that a qualitative life span up to at least 115 years of age is reasonably attainable by the average person if they start working on it no later than about 50 years of age, though earlier is much better.
Walford's principles of extending life are very simple. All you have to do is restrict your caloric intake to about 1,500 per day, and water fast two days a week. Or alternatively, reduce your caloric intake to 1,200 per day and fast only one day a week on water. And make sure that every single bit of food you do eat is packed with nutrition, every single calorie, without exception. You continue this program for the rest of your life along with moderate daily exercise and high but reasonable dosages of vitamins, minerals, and also take a few exotic food supplements. The supplement program is not particularly expensive nor extreme, Walford's supplement program is more moderate than the life extension program I recommend for all middle-aged and older people. The best foods for this type of program is a largely raw food diet (80%) with a predominance of sprouts and baby greens, some cooked vegetables, and raw nuts and seeds. And make sure you get 30 minutes of cardiovascular exercise every other day.
While Dr. Walford's focus is on caloric reduction while maintaining sufficient nutrition, most other life extensionists focus on increasing the nutrition side of the equation for health without bothering to reduce caloric intake. This approach is much easier because essentially, it involves gobbling nutritional supplements by the handfuls without requiring self-discipline, though it can get quite expensive. I'll have more to say about this approach in the next chapter, which is about vitamins.
In this book I can't explain all the aspects of prolongation of life through conscious life-style choice. Those who are interested are referred to the Bibliography.