I know of a guy called Jack Lalanne who is now aged 97 and he works out 3 hrs in the gym everyday and works another ten hours at his business. He was a sickly youth at age 14 and he was told the cause of his health problems and when he followed the advice that followed they disappeared. He has been following that advice for 83 years. This is a video of him 2 years ago publicising his book How To Live Forever. See the food advice at ReallyHealthyFoods
