Book excerpt: Twelve years ago, renowned physician and author Dr. William Sears was diagnosed with cancer. He, like so many people, wanted -- and needed -- to take control of his health. Dr. Sears created a comprehensive, science based, head-to-toe program for living a long, fit life -- and it worked. Now at the peak of health, Dr. Sears shares his program in Prime-Time Health. This engaging and deeply informative book will motivate readers to make crucial behavior and lifestyle changes. Dr. Sears explores how to keep each body system healthy and delay those usual age-related changes. Written in Dr. Sears's wise, accessible, and entertaining voice, Prime-Time Health is a practical program to help you live your best life possible-pain-free, disease-free, stress-free, and medication-free.