Growing older, I have become to wonder more about the degree to which our lifestyle decisions can influence our health later in life.

Of course, we are all aware of the benefits of a healthy diet and exercise, but who is to say that Willie isn't doing exactly what she should be at 77 years? If any given 70-year-old that was reasonably healthy set out to have Willie's physique at 77, what percentage of them would be physically capable of accomplishing it?