I have had people ask me, ‘what is it that you actually do?’
Actually this question is much tougher than it appears on the surface. My professional field is Public health or Health Promotion, however you want to say it. However the mechanics of that can be difficult to explain.
At its simplest I take current health knowledge, based on research, and synthesis it into simple guidelines for people to follow.
So while you might read up about a diet, I also can tell you about its health implications, what a lack of sleep will do to it, levels of activity ETC.