The association between fast food consumption and body mass index among students aged 14 to 16 years old at SMK Shah Alam

Adolescence is a critical period for developing healthy dietary habits that can significantly impact long-term health. However, the growing consumption of fast food, known for its high calorie content and low nutritional value, has contributed to rising obesity rates among adolescents. The objective of this study was to determine the association between fast-food consumption and Body Mass Index (BMI) among adolescents aged 14 to 16 years old at SMK Shah Alam. The study utilised a quantitative cross-sectional method. Respondents completed a bilingual self- administered questionnaire on sociodemographic background and a fast-food frequency questionnaire. The researcher measured the weight and height of the respondents. The results showed that a total of 300 respondents aged 15.29±0.732 years (45.7% males, 54.3% females) participated in this study. 96.3% of students consumed fast food at least once a month, with 31.7% eating it 2-3 times per week. Their average BMI was 22.64±4.3843. Furthermore, BMI classifications showed that 43.3% were overweight or obese, 13.0% were underweight, and 43.7% had a normal weight. A Pearson chi-square test revealed a significant positive relationship between fast-food consumption frequency and BMI, χ² (1, N = 300) = 30.845, p < .001. These findings underscore the importance of public health interventions, such as school- based nutrition education programs, the provision of healthier food alternatives in school canteens, and increased parental involvement, to promote better eating habits and address the growing obesity issue.