Test Results

well, my tests came back decent. chest x-ray showed no signs of lung cancer (great news). EKG was good and my blood tests came back ok as well. though i am lacking in iron and protein, it is still not major (i just need to start taking vitamins i guess). but maybe i don't. this brings me to the whole "blood test procedure" questions.
why do they advise you not to eat or drink anything 12 hours before a blood test just to tell you that you have low iron and protein in your system? shouldn't we be able to go about our normal routine and intake of foods before a blood test? that would be the most accurate of results i think. my normal morning is 2-3 cups of coffee with milk and sugar, so if i am denied that, then my sugar will be lower than it normally is at 8am. thereby making the results that they got while i was fasting, completely false compared to what my blood results would normally be.
now seeing how i graduated high school through a summer school program, i am sure (insert sarcasm here) that the doctors would know more about my body than i do. i am just making an obvious observation about medicine and how i think it should be performed.
everyone may be created equal, but our bodies are not.