As a muslim driver I feel I should share my point of view on this topic.The act of fasting itself can be broken into two categories ie the spiritual act and of course the physical demands. In support of all the scientific facts put forward in regards to blood sugar levels, dehydration etc etc I must re-iterate that the Islamic Faith states that those muslims who are travelling (in our case flying) may break their fast during their travels and repay it (by fasting) on another day.Now faith is a funny thing and for most muslims its more so a test of mind over matter.Something science itself supports that when we are so determined it can overcome the low blood sugar levels and dehydration etc etc....I am not implying that all muslim pilots have that certain amount of determination I am just trying to open you to that possibility that most of us do and hope that our non muslim collegues be a little more understanding of those who have decided to fast while flying.When I board an airplane believe that whoever is sitting up in the cockpit is a responsible professional who knows his/her limitations and makes the right decisions with flight safety as his/her number one goal......not just muslim pilots who are fasting but also to all of us who share the same sky.