In reply to mypyrex: Cheyne-Stokes varies, some do and some dont. I use to get it above 4000m but now only occasionally and then above 5000m. Others have never had it.
Loss of appetite seems to be a mixture of cant really be bothered and also everything tastes bland, which is why on expeditions some take really strong flavoured items.
Main problem is not drinking sufficient but not feeling thirsty and its only when you realise your rubbery legs are part due to dehydration as to exhaustion.
But rarely should there be issues on AC since you are starting at 800m and very gradually going up the pass. Its a lot easier than EBC where you are in Lukla and 2800 from the start.
Dont fret so much about it.