Doug Lerner wrote:

This week I've lost 1.5 kg so far and the week isn't quite over yet. The
only thing I changed is what I'm drinking.

I am really beginning to suspect that Diet Coke adversely affects diets
in a way that has more impact than mere temporary fluid retention. Could
the listed calories be untrue?

Diet Coke has aspartame. Some have problems with aspartame
some don't. When my wife has any aspartame at all not diet
works for her; it blocks her loss somehow. I don't get
that effect.