Is your colleague a coffee drinker? It's common for muslims who regularly consume caffeine to go through withdrawal the first week of fasting. This can cause ex

Is your colleague a coffee drinker? It's common for muslims who regularly consume caffeine to go through withdrawal the first week of fasting. This can cause excessive tiredness and headaches. Also during Ramadan its common to make longer prayers at night, which can disrupt sleep. Personally I just make sure I get enough sleep (even by taking naps during lunch) and taper off caffeine before Ramadan starts, and then I feel just as productive in Ramadan while fasting vs not.