I think perhapse you would, but I highly recommend that you don't. First off, you will get brutal "gut rot" the feeling of having that chemically mix in your stomach with nothing else at all. Also, goes against principles of a fast, which is to yes loose weight, but also to cleanse and start a new healthy Diet fresh.
hope that helps, sorry if its not the answer u wanted to hear!

you would be better off having a juice than a soda.
you will still lose weight and wont feel sick from the soda.