what kind of diet do you do while ON?
I don't really get the question... the diet whether on or off has no major difference, the gear will simply bring results fasters (bulking) or help keep LBM (cutting).
The diet is the main factor and everything else rotates around the diet, not the cycle...
Having said that, we all respond differently to diets, so while some peple swear by a CKD some will do just as good with a med-carb diet.
What do you want to do? cut? bulk? maintain? it all goes back to your maintenance cals, if you don't know them, that is your starting point