Health class

The most important thing that I learned in class today was how abstract the term "healthy" is. It's interesting how everyone has a slightly different understanding of what "healthy" even just in our classroom. This makes teaching health a difficult topic to tackle, since a student's perception of health will inevitably differ from our own. Who are we to judge whether or not a behavior is truly healthy or not for an individual? I wonder if there is a medically or universally accepted definition that everyone can use as their standard when discussing such an abstract issue such as health.