I try to promote health by encouraging my parents (mostly my dad because my mom listens to me anyway) to eat organically and to minimize the amount of animal products and processed food they eat.
I try not to tell people that what they eat is "bad", I prefer to say it's "unhealthy". I also encourage people to do research on the foods they eat. I mean, even I will eat an egg or get a piece of cheese every now and then. But, instead of getting say... Kraft, (which is processed crap) I will get my cheese from local farms. Or instead of eating an egg from the grocer, I'll buy it from my local feed store which sells eggs from nearby family farms. So the eggs are cage free, free range and there's no animal abuse or horrible chemicals that the chickens are being fed. C:
My mom on the other hand promotes exercise. She always goes to the gym and works out for at least an hour every day. She helps me to get my ass in gear and exercise more.

I am more of a healthy eater, but it takes both a healthy diet and exercise to be healthy.
For me, meditation and taking my daily meds is also beneficial for my health. Well, my mental health anyway. But I feel that mental health is just as important as physical health. People need to get sunlight and people need to do what they can to maintain mental health too.