If by "health" we mean reducing the risk of common, preventable illnesses, I would say the following should be your top priorities, in no particular order:
Walk for at least 30 minutes each day at a brisk pace.
Eat less food than you feel hungry for and focus on fresh produce and a moderate amount of lean protein.
Get adequate, regular sleep.
Sit in a heels down, full depth squat for a total of at least 10 minutes each day.
Live somewhere with clean air and water. Get lots of both.
Have a well developed social network of family and friends and be involved in your community.
Manage your psychological stress and find a way to enjoy your work.
"Fitness" is a whole other question.