Our bodies change as we age, and to remain vigorous, active and healthy in our middle years and beyond requires that we supply them with good nutrition and regular exercise. It’s almost too simple, isn’t it? However, staying faithful to a healthy lifestyle requires commitment and self-discipline, and an understanding that you are the one who must make the appropriate choices. When you enter your middle years at age forty, you can no longer ignore the relevance of diet and exercise to health even if you did so in your youth.