Does bottle size affect the amount of cola consumed at home?

We assessed the feasibility of running a trial on the impact of bottle size on in-home consumption of cola, in which households received a set amount of cola each week for four weeks, in bottles of one of four sizes (1500 ml, 1000 ml, 500 ml, or 250 ml). 16 households were tested and we found the procedures to be both feasible and acceptable.

Issues associated with the study design were identified, which may impact the validity of the primary outcome (consumption). These include consumption driven by study-determined supply and a failure to capture out-of-home consumption. Methods to avoid these would be needed before conducting a definitive trial.

Impact of bottle size on in-home consumption of sugar-sweetened beverages: a feasibility and acceptability study. Mantzari, Hollands, Pechey, Jebb & Marteau, 2017.

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