listen its like this
amir khan fasted last ramadan and won his fight
he didnt fast this ramadan and lost in 54 seconds...
*LOL*
allow it hehehe
personally it doesnt start getting to me till around 6pm by which time if i was a surgeon i wud b sitting at home.
the only jobs that i'd think twice if i should fast would be the physical ones. you dont really lose concentration just cause your hungry but you would suffer if your thirsty mid-afternoon doing heavy labour.
but great question though.