This is an interesting hypothesis and offers another possible explanation of why both diet and sugar-containing sodas cause you to gain weight. However, the data are very preliminary. This study: wedding collections for fat plus size brides
Was primarily done with rats.
Did not include carbonated water. If it is carbonation that is causing the weight gain, this is an essential control.
Furthermore, the human component of the study only had 20 subjects and did not directly look at the effect of carbonation on weight gain.
This hypothesis is not ready for prime time. Much more study is needed.See More