What role should experts play in our decision making?

Specifically, is it irrational to differ to experts on topics which we ourselves are not (and frequently cannot) be well-enough informed on to make a rational decision ourselves? For example, diet is a complex topic, one which requires years of study to truly understand. I've chosen to spend those years learning something else. I expect dieticians to accept that I know more about geology than they do; shouldn't they have the same expectation of me? (Please note that I'm not saying the Paleo Diet is good, bad, or indifferent--it's just that your discussions of that diet brought the question to mind.) Or, put another way: Is differing to an expert when struggling with some behavioral question (morals, diet, etc) any different, philosophically, from differing to an electrician when your fuse box goes bad?