I just started reading "Quantum Wellness" by Kathy Freston and I really liked what she has to say about wellness. The book is about emotional and spiritual wellness, as well as physical wellness:
Wellness begins by paying attention to the little stuff, and then it swells in momentum until we find ourselves on a whole new playing field. We start by taking a look at our lives with honest eyes and then setting a few clear intentions to change. We take a small step here, and another there, and before we know it, we are made new.
Wellness is not so much a goal as a process, a journey, a way of orienting yourself toward life. It’s a feeling of total participation that involves being in balance in the three key dimensions of body, mind, and spirit, and always looking at your actions and responses to life as they affect these three dimensions and are affected by them.