Eating fruits and vegetable will kill cancer cells (before they grow God fobid as the immune system is constantly doing) so we should ensure at least five helpings of fruits and vegetables daily
Being happy will a. Bring Moshiach (as happiness breaks the boundaries of galus) Will lead to happiness (pretty obvious) Will bring prosperity (as happiness breaks boundaries) Will lead to friendship (for a happy person is a giving person and a giving person has friends) Will merit the world to come (as in the story with Elijah) Will prevent us from indulging in many unhealthy forms of behavior (such as overeating) to compensate for our feeling down
Studying Torah, especially Chassidus makes us into better people (for the light of God within gets internalized in us and we become more sensitive people)
Giving is what its all about (and the reason we find it hard is because God would like to reward us for challenges overcome.)