I gave up regular coffee when I started LCing. Went right to decaf--- as far as I know decaf IS allowed. I drink my 1 1/2 cups in the morning and then have a cup early afternoon.

At one time, I used to drink pots of regular (all day long) and I gradually cut it down and had no ill effects. Then I was able to switch to decaf and never look back!
So.... gradual is probably better.

Ellie