I am paraphrasing you here:
1.) Eating quality food
2.) Exercise regularly
3.) Sleep enough
4.) Drink enough water
I think these 4 simple acts can do wonders for people if they actually follow them. Let me add the following:
1.) Eating quality food (a balanced breakfast, lunch and dinner with no skipping or over-indulging)
2.) Exercise regularly (90 min. in the gym or something similar, 4 times a week)
3.) Sleep enough (8 hrs minimum)
4.) Drink enough water (7 cups a day)