Food consumption data gathered at a fine enough spatial and temporal resolution is essential for the effective delivery and evaluation of diet-related public health interventions. Currently, the standard for food consumption data is food surveys. However, they are a burden on the respondant, are prone to bias and are often published after a long delay. In our study, we illustrate the utility of digital food purchasing data in public health practice by demonstrating a drop in soda sales following two public health interventions implemented in late 2011 in Montreal, Canada, to decrease the consumption of soda in school-aged children.