A cross-sectional study of the nutritional quality of new south wales high school student food and drink purchases made via an online canteen ordering system

Unhealthy dietary patterns in adolescence are associated with an increased risk of future chronic disease. This study aimed to assess online canteen lunch purchases made by high school students to identify: (1) the nutrient composition of purchases (energy, saturated fat, sugar, sodium, percent energy from saturated fat and total sugar); (2) the proportion of items classified as healthier (‘Everyday’) and less healthy (‘Occasional’ or ‘Should not be sold’) according to the New South Wales Healthy Canteen Strategy; (3) the frequency of purchases by product type (e.g., salty snacks), their classification and nutrient composition; and (4) associations between student characteristics and the nutrient composition and classification of purchases. The average order contained 2075 kJ of energy, 6.4 g of saturated fat, 18.4 g of sugar and 795 mg of sodium. Less healthy (‘Occasional’ and ‘Should not be sold’) items combined accounted for 56% of purchases. The most frequently purchased products were burgers and crumbed/coated foods. Students in higher grades purchased a significantly higher mean percent of ‘Everyday’ items, compared to students in grades 7 or 8. The majority of high school student purchases were less healthy (‘Occasional’ or ‘Should not be sold’) items, warranting further investigation of factors influencing online canteen purchasing behaviour in this setting.