Association of Body Mass Index with Nutritional Knowledge and Dietary Practices among Early Adolescents: Evidence of a Knowledge and Practice Gap

Background: Obesity in children and adolescents is becoming a major public health issue, especially in developing nations that are rapidly changing their dietary habits.In this context, dietary patterns, lifestyle habits, and awareness of nutrition and gut health may all influence anthropometric outcomes.Objectives: To assess the association between nutritional knowledge, dietary, and lifestyle behaviors, gut microbiota and probiotics awareness, and anthropometric measures among early adolescents.Materials and methods: A cross-sectional survey of 500 adolescent students was conducted.A systematic questionnaire was used for collecting data on lifestyle factors, dietary practices, sociodemographic traits, and knowledge of nutrition and gut health.Body mass index (BMI) was classified according to the Indian Academy of Pediatrics (IAP) guidelines, and anthropometric measurements were recorded.Descriptive statistics, Chi-square testing, correlation analysis, and logistic regression were used to identify predictors of BMI risk.Results: Most participants had a normal BMI (70.8%), with evidence of undernutrition (8.6%) and overweight/obesity (20.6%).Nutritional status was significantly associated with socioeconomic status (p < 0.001).No significant associations were observed between BMI and diet type (p = 0.632), diet score (p = 0.296), or sleep duration (p = 0.077).Logistic regression identified socioeconomic status (OR = 2.97, p < 0.001), screen time (OR = 0.372, p = 0.001), and gender (OR = 0.588, p = 0.030) as significant predictors of BMI risk.A knowledge-practice gap was observed, as general awareness of healthy eating was not associated with dietary behaviors.In contrast, knowledge of probiotics and gut health was significantly associated with corresponding practices (p ≤ 0.001).Conclusion: Nutritional status among adolescents appears to be influenced more by socioeconomic and lifestyle factors than by dietary patterns alone, underscoring the need for targeted, practical nutrition education approaches.