"Performance in most companies, institutions and government departments around the Arab world is usually at a low during the month of Ramadan, with poor productivity and constant reported absences. Dubai sought to change this concept through restructuring the day, turning Ramadan nights into meeting times to complete the unfinished work; but low productivity remained a feature of this month.[...]constant absence had become a feature during Ramadan because of the wrong perception that this month was a month for rest, when it was in fact the month of worship and hard work.[...]Meanwhile, Dr. Musa'ab Al-Zubair described Ramadan as a "month of medical reports" where most employees resort to sick leaves as a good alibi which indeed negatively affects work productivity."Kuwait Times/Kuna September 24, 2007
Maybe they are just too devout to work, or maybe they really aren't feeling too well after all. Here's an interesting blogpost by a former Muslim who finally enjoys normal eating during Raman:
"I couldn't concentrate in school. I had nasty heart burn all morning, because we'd wake up at an ungodly hour to gorge! [...] There are many women in my life and some of them are extremely old with various medical conditions. They all feel compelled to fast. It drives me insane!"