Going off on a slightly different tack on this one - there will be days where you don't lose weight. In fact, there will be weeks where you don't lose weight.
People will tell you different things - for example, that they think they can't have CD bars because the week they had them, they didn't lose weight. Or it must because they had water flavourings, etc.
But it's really unlikely that any legitimate CD item (used in its correct amounts) will affect your weight loss. Far more likely that you're just retaining water. Our bodies aren't machines. If they were, most of us would lose something like half a pound every day if doing SS. But they aren't. You're still losing that half a pound per day - but it won't necessarily show up on the scales until later. Maybe not until a week later. That's why some weeks, you lose 6 pounds and the following week, you only lose 1. In reality, you've lost 7 pounds in 2 weeks.
I remember being told it can cause bloating, but have never been able to find anything that supports this....
I drink fizzy water if I go out as it seems a bit more 'special' and rotate between plain and fizzy when plain gets too tedious