I have struggled with maintaining low carb status. But, low carb liquids that I have found that taste good are crystal light to go packs that I put in a bottled water, no sugar added popsicles, chicken boullion cubes (2) for 16 oz. of H20 in a large mug in the microwave for 3 mins., and then I also ordered products from bariatriceating.com... they have some potent protein drinks (3oz. fluid with 42 g protein / low carb)... I don't like these as much but they pack a great protein punch with very low or no carbs. The website has other items that I do like but they are for when you can have more than just clear liquids. I actually made up a protein shake in the blender yesterday that tasted gooood. It was one pack of the to go crystal light packs (classic orange), about 6-8 ice cubes, 1/2c of skim milk, a frozen banana, and 2 scoops of vanilla protein powder from GNC (40g protein). I think next time I will try to decrease the carb content more by trying to use kroger carbmaster plain yogurt and a pack of splenda or carbmaster vanilla yogurt instead of the banana and milk.
Best of luck...