For me, I think you want to eat good food, drink clean water, breathe good air, get lots of sleep, get lots of exercise, and do activities that keep you mentally sharp. Also avoiding anything in excess that can lead to negative consequences. This is why it's good to live somewhere with a lots of trees for good air, consider drinking clean water as opposed to soda, get lots of sleep, have a hobby that keeps you moving and thinking, and be somewhat conscious about what you eat.
Think this is just what every one needs but the situation of life have deprived alot of this things.
For me, as a very young man who is still growing, I have set this as the ideal goal, a life where I can have a good (healthy) food, drink clean water, have my rest as needed, regular workout (Exercise) and the rest of things in life wouldn't be my problem. As long as my desire is coming true and I'm making progress with my photography life, I believe I will be more healthy than ever.
If anyone could get all this, then happiness is not gonna be the problem because all this is happiness already.