Food purchasing practices in various retail settings and dietary intake: A cross-sectional survey of Australian adolescents

Background/Aims: Discretionary, energy-dense, nutrient-poor food and drinks are heavily marketed and readily available in retail settings frequented by adolescents. This study examines associations between food purchasing practices in various retail settings and dietary intake among Australian adolescents.Methods: Participants were students in years 8 to 11 (ages 12-17 years) who completed the 2009-10 (n = 13 790), 2012-13 (n = 10 309) or 2018 (n = 9102) National Secondary Students' Diet and Activity (NaSSDA) cross-sectional survey. Multistage stratified random sampling was used. An online survey completed at school assessed self-reported frequency of food purchasing practices in various retail settings and consumption of discretionary food, sugary drinks, fruit and vegetables. Generalised linear regression models examined associations between food purchasing practices and dietary behaviour.Results: Relative to students who brought lunch from home, those who purchased lunch from school or nearby outlets reported higher intake of discretionary food and sugary drinks and lower fruit intake. Buying lunch from school was also associated with lower vegetable intake. Buying food or drinks on the school commute, outside school grounds during school hours, from supermarket checkouts, and using mobile phone apps were each associated with higher discretionary food and sugary drink intake (all P < .01).Conclusions: Purchasing food or drink in various retail settings is associated with higher intake of discretionary food and drink among Australian adolescents, and some purchasing practices appeared to displace fruit and vegetable intake.

Automated summary

This study examines the associations between food purchasing practices in various retail settings and dietary intake among Australian adolescents. The results showed that purchasing lunch from school or nearby outlets was associated with higher intake of discretionary food and sugary drinks and lower fruit and vegetable intake. Buying food or drinks on the school commute, outside school grounds during school hours, from supermarket checkouts, and using mobile phone apps were each associated with higher discretionary food and sugary drink intake.