General procedure
ABM
RECRUITMENT
Part of the method of the present study is identical to a registered report from our groupThe study was carried out fully online. The recruitment procedure directed the participants to an online website to sign informed consent forms. Once done, the website was screened for inclusion/exclusion criteria using a custom health and drinking frequency questionnaire. They then were randomly assigned to one of the control or experimental interventions. We provided them a link to download the assigned intervention, along with a booklet explaining it. The exact hypotheses of the intervention were explained to every participant in both groups (i.e., reducing the valuation of unhealthy items and in turn reducing their consumption). However, we did not inform them of the existence of the control group or the rationale behind the stimulus–response mapping rules.Our laboratory engineer randomly renamed the experimental and control interventions Condition 1 and Condition 2, thus preventing the experimenter from inferring the participants’ condition assignment, and in turn ensuring double blinding during the data analyses.Before they could start the training, all participants had to report their soda consumption from the past day and completed the analogue scales of the items’ valuation on their device. We only used the highest rated healthy and unhealthy items (above the median) during the training.We asked the participants to report their soda consumption from the past day on two random weekdays for each week of the intervention.The participants were asked to train for a minimum of 20 min (a minimum of 10 min of GNG and a minimum of 10 min of ABM), 5 days a week for 4 weeks, in order to complete the intervention. At any time after the fifth completed day of training, the participants were able to end the intervention, fill out the same analogue scales of item palatability, and then be redirected on the website to fill out the core module of the Game Experience Questionnaire