WOE= way of eating for more acronyms click on this:
http://forum.lowcarber.org/showthread.php?t=88926

There were many threads about caffeine. It seems to me, that the majority of people here still have his/her one cup of coffee.
The many people who decided to give up coffee/sodas usually experienced some wihdrawal symptoms - those can be annoying, but disappearing after a couple of days.

I lost 35 lbs without stall - meanwhile keeping my ONE morning espresso. (But not having any other coffeine drink sodas, tea etc.)
I think the key word is : moderate. I do not remember to read from anybody consuming HUGE amount of coffee, sodas etc.

It is your choice:-)))

You mentioned you "consider Atkins". I would recommend you to discover more options. Click on the "Which low-carb plan is right for me?" on the right side of the screen. (No, I am not talking against Atkins, only would like to offer more chocies:-)