You've acknowledged it's irrational, so making rational points in rebuttal is clearly a pointless exercise. Nevertheless... If you are already worrying about "

You've acknowledged it's irrational, so making rational points in rebuttal is clearly a pointless exercise. Nevertheless... If you are already worrying about "obvious" things, wouldn't it be better to know whether or not you have anything to worry about? For instance, if it turns out you have a below-average chance of heart disease, it might make you worry less about your weight. On the other hand, if you discovered that you were (like me) at elevated risk of developing diabetes, wouldn't that provide the extra motivation you need to limit your suger intake and further control your weight? I can't see any situation where having less data would make things demonstrably better -- just more uncertain.