Trying to condense what the most important ingredient of human beauty is into one thing is difficult. But what I've concluded is that it's attitude. It is the attitude of self-worth, supported by the belief that you were created intentionally, not by some random accident, for a high calling. This then should result in one having the consistent purpose to tend to and care for their spiritual, mental, and physical health, with an attitude of stewardship for the good gifts one has been given.
When I observe people who are obese, or smokers, or who over indulge in alcohol, or recreational drugs, or any number of other health-damaging behaviors, I wonder why. I guess a lot of people were not trained to believe that they were meant to have a calling in life. So they just work for what ever short-term pleasures they can obtain. It makes me sad.