For starters, you must live up to what you fight for, so adopting a healthy lifestyle is the first obvious step. Also, considering the absurdly broad scope of the "health" definition (from the WHO, for example), you would have to decide on a specific focus. (i.e. alternative medicine? Nutrition and fitness? Access to global healthcare? and so on). Among the career paths you could pick, there are: *Becoming a health educator, by writing or broadcasting TV/ Youtube shows on wiser health choices; *Visiting countries where people lack basic resources in nutrition and diet, urban sanitary infrastructure, and/or healthcare advances (like vaccines); or perhaps other places where there has been a rise of non-trasmissive chronic diseases (e.g. obesity, hypertension, diabetes). The purpose is really to educate people on ways to overcome the causes and to bring awareness to the problems. *And finally, you can be a personal trainer/dieter to individuals or groups.
