I'll answer your questions to just give you an idea. firstly, you can talk about health in general... what do your parents tell you about health? i guess they advice you to always wash your hands before eating, to wash your teeth, not to smoke or consume alcohol, to eat healthy food and not fast food etc. for the second question, seeing what you've wrote above, it is obvious that what you're parents are telling you is always sensible. for the third, it is up to you if you take the advise or not.