Nutritional knowledge and physical activity in relation to healthy lifestyle adherence among Universiti Kebangsaan Malaysia (UKM) students

University students face increasing challenges in maintaining a healthy lifestyle due to academic pressure, changing living conditions, and limited time. While nutritional knowledge and physical activity are known contributors to health behaviors, the relationship between these factors and lifestyle adherence remains underexplored among Malaysian university students. This study aimed to determine the effectiveness of nutritional knowledge and physical activity status on adherence to a healthy lifestyle among health science and non-health science students at Universiti Kebangsaan Malaysia (UKM). A cross-sectional study was conducted among 169 undergraduate students from the health science and non-health science faculties. Participants completed a self-administered questionnaire incorporating the General Nutrition Knowledge Questionnaire (GNKQ), the International Physical Activity Questionnaire (IPAQ), and selected domains of the Health-Promoting Lifestyle Profile II (HPLP-II). Data were analyzed using descriptive statistics, chi-square tests, independent t-tests, and Pearson correlation. Health science students scored significantly higher in nutritional knowledge compared to non-health science students (p < .05). However, no significant difference in physical activity levels was observed across academic disciplines. The majority of students demonstrated moderate adherence to healthy lifestyle behaviors. A weak but statistically significant correlation was found between physical activity and healthy lifestyle adherence (p < .05), while the relationship between nutritional knowledge and lifestyle adherence was also significant but weak. Although nutritional knowledge and physical activity contribute to healthy lifestyle behaviors, their influence alone is insufficient. Psychosocial and institutional barriers likely moderate students’ ability to translate knowledge into consistent health behaviors.