[The purchase behavior of prepackaged food and its determinants among primary and middle school students in 6 provinces of China].

To examine the purchase behaviors of prepackaged food and its determinants among primary and middle school students in 6 provinces of China. A multi-stage sampling strategy was adopted to select 2 499 primary and middle school students and their parents from the eastern region of China(Beijing, Jiangsu Province, Guangdong Province), the northeast region(Heilongjiang Province), the central region(Henan Province) and the western region(Sichuan Province) from July 2020 to March 2021. Socio-demographic characteristics of students and their parents, eating-related behaviors and the purchase behaviors of prepackaged food of students, and parents' attitudes towards students' eating behavior were collected through questionnaire towards students and their parents. The χ² test was conducted to compare the purchase behaviors in different groups of students, and multivariate logistic stepwise regression analysis was used to analyze the determinants among primary and middle school students. The age of 2 499 participants was(12.7±2.5) years. There were 1 272(50.9%) females and 1 279(51.2%) middle school students. About 1 404(56.2%) students bought prepackaged food. The top 6 prepackaged foods bought at least once a week were milk and dairy products(74.6%), baked food(58.7%), beverages(42.8%), puffed food(40.8%), chocolate and candy(39.8%), and nuts and dried fruits(37.5%). The multivariate logistic regression model analysis results showed that compared with primary school students, rural students, non-boarding students, students who did not like snacks and students whose parents paid attention to their children eating snacks, middle school students(=3.36, 95%2.73-4.12), urban students(=1.33, 95%1.11-1.61), boarding students(=2.15, 95%1.66-2.79), students who liked snacks(=2.01, 95%1.66-2.43), students whose parents did not pay attention to their children eating snacks(=1.27, 95%1.05-1.54) were more likely to buy prepackaged food by themselves. Compared with students whose parents had education level of junior high school and below, students whose parents had education level of undergraduate and above(=0.70, 95%0.53-0.92) were less likely to buy prepackaged food by themselves. Compared with students whose family monthly income was less than 5 000 yuan, students whose family monthly income was over 10 000 yuan(=0.67, 95%0.52-0.87) were less likely to buy prepackaged food by themselves. Many primary and middle school students buy prepackaged food by themselves in 6 provinces of China. Individual characteristics such as grade, place of residence, boarding status, as well as family environment such as parents' education level, monthly income and concern about children eating snacks are the influencing factors of purchasing prepackaged food.