The paper, Association of a Workplace Sales Ban on Sugar-Sweetened Beverages With Employee Consumption of Sugar-Sweetened Beverages and Health explores what happened to sugar-sweetened beverage (SSB) consumption in the 10 months after the University of California at San Francisco banned their sale from campus and medical centre venues (including in their cafeterias, vending machines and retail outlets). People were of course still free to bring whatever beverages they wanted to work or school. Specifically researchers were interested in the impact the sales ban would have on those with heavy SSB intake (defined as a pre-intervention consumption of more than 12 fl oz daily for the prior 3 months).
For two months prior to the intervention, they canvassed for heavy intake participants, and once the SSB sales ban was enacted, half were randomly assigned to receive a 15 minute motivational intervention targeting SSB reduction, half were not, and 10 months later, all of their intakes were again explored.
The findings weren't particularly surprising. When SSBs aren't sold, fewer are consumed.
How much fewer?
Half as much overall, with those receiving the brief motivational intervention seeing their consumption decrease by roughly 75%, and those who didn't by 25% (though it should be noted, especially among those who received the motivational intervention, social desirability bias may have influenced their self-reported consumption reductions).
Bottom line though, it certainly stands to reason that if you don't serve or sell it, we won't eat or drink it, or at the very least, we'll eat or drink much less of it, and so as far as public health interventions go, likely wiser to reduce access to hyperpalatable and indulgent fare rather than simply encouraging people to just eat less of them.