I found that it was giving me bad headaches, but I just couldn't do without it - I think that's called "an addiction"!! I limit myself to one bottle over the weekend and during the weekend keep myself topped up with black tea, water and cordial juice - I survive, but its just not diet coke!!
Wine is fat free too. Its the calories in wine thats the problem. I can have wine and not have any effects of the scales.
Only real booze that you need to keep clear of is cream based ones like Baileys at the like. All other booze is fat free, but just keep check on cals. They wont effect you on the loo when taking the tabs, but you can still slow the weight loss down if you have far too many calories.