“…In line with the different results of previous studies on portion size influenced by social and psychological contexts, we also found that most studies on eating behaviour apply behavioural measurements in experimental settings (such as in the US, UK, and the Netherlands) using behavioural measurement, lab-based experiments, observations, and online experiments (Baker et al, 2019;Hermans et al, 2012;Otterbring, 2018;Robinson et al, 2022;Ruddock, Long, et al, 2021). However, in Indonesia, there has been a heavy reliance on subjective measurements, including self-reporting, surveys and FGD (Dewanti et al, 2022;Habibie et al, 2019;Risti et al, 2021), yet few studies have used behavioural measurements of food choices and portions. Indeed, behavioural measurement studies provide observable data without requiring participants to report their inner states.…”