Abstract: Objective To explore the relationship between dietary patterns and physical and mental health of senior high school students in Shandong Province. Methods The study was conducted using probability proportional sampling, resulting in the inclusion of 1,102 eligible senior high school students. The dietary data of the senior high school students were collected using a simplified food frequency questionnaire, physical fitness data were collected using the National Physical Fitness Test, and mental health data were collected using the Symptom Self-Assessment Scale(SCL-90). Principal component analysis was used to construct different dietary patterns, and the study participants were divided into Q1-Q4 groups according to the dietary pattern factor scores; multiple linear regression was used to analyze the relationship between dietary patterns and physical fitness and mental health. Results Principal component analysis revealed 3 main dietary patterns: beverage-fast-food pattern, meat-egg-milk-fruit pattern, and vegetarian pattern. In terms of physical fitness, the beverage-fast-food pattern was significantly and negatively associated with the physical test score(model 1: β=-3.86-1.76, P<0.05), but after controlling for potential confounders, only the Q3 and Q4 groups maintained a significant association with the total physical test score(P<0.05). The meat-egg-milk-fruit pattern was positively associated with the total physical test score in model 1(β=2.21-2.27, P<0.05), but the association was no longer significant after adjusting for confounders(P>0.05). Vegetarian pattern was not significantly associated with total physical test score(P>0.05). In terms of mental health, the beverage-fast-food pattern was positively associated with the total SCL-90 scale score(model 1: β=0.11-0.13, P<0.05), and the association was no longer significant after controlling for confounders for the Q3 group only(P>0.05). The high score of the vegetarian pattern was negatively associated with the total SCL-90 scale score and remained significant after controlling for confounders(P<0.05). The meat-egg-milk-fruit pattern was not significantly associated with the total SCL-90 scale score(P>0.05). Conclusion The high proportion of beverage-fast-food diet pattern among high school students in Shandong Province is significantly associated with physical health and mental health problems. The meat-egg-milk-fruit pattern is beneficial to physical health but has no significant effect on mental health. The vegetarian pattern has potential protective effect on mental health. The importance of individual health counselling is emphasized. It is recommended that schools, families and public health authorities develop targeted interventions accordingly to improve adolescents dietary patterns and promote their overall healthy development.

Key words: Dietary patterns, Senior high school students, Physical and mental health, Multiple linear regression, Principal component analysis