A major study into whether calorie labelling on fast food menus reduces the amount customers purchase has concluded that it does – but there is a limit to how long the effect lasts.
Sales data from a chain of 104 restaurants in the southern USA over a three-year period was used for the Harvard University study, which was published in medical journal BMJ.
At the end of the research, the BMJ reported that a small decrease in mean calories purchased per transaction was observed after the implementation of calorie labelling.
However, it said the reduction “diminished” over one year of follow-up.
Researchers carried out the study to evaluate whether calorie labelling of menus in large restaurant chains was associated with a change in mean calories purchased per transaction.
All of the data was taken from a national fast food company with three different restaurant chains located in Louisiana, Texas, and Mississippi between April 2015 and April 2018.
More than 49 million transactions took place during the period and 242 million items were purchased.