Nutrition knowledge, eating behavior and body-cathexis: Results from the body mass index perspective of adolescents

Background During adolescence, nutritional literacy, eating behaviors, and body image play important roles in body weight management. Aim This study aimed at the relationships between nutritional literacy, eating behaviors, and body cathexis according to BMI in high school students. Methods This study was designed as a cross-sectional study including 568 students (73.6% female) aged 14–18 studying in four different high schools in Ankara, Turkey. Data were collected using a questionnaire that included sociodemographic information, the Adolescent Nutrition Literacy Scale, the Dutch Eating Behavior Questionnaire, and the Body-Cathexis Scale. Summary Critical nutrition literacy scores were significantly lower in overweight than underweight adolescents ( p = 0.014). BMI showed a weak positive correlation with interactive nutrition literacy ( r = 0.107, p < 0.001). External eating scores were lower in obese adolescents and negatively correlated with BMI ( r = −0.149, p < 0.001), whereas restrained eating showed a moderate positive correlation with BMI ( r = 0.437, p < 0.001). No significant association was found between BMI and emotional eating ( r = 0.250, p = 0.905), and body cathexis scores were lower in obese adolescents. In multivariable regression analysis, restrained eating emerged as an independent positive predictor of BMI, whereas body cathexis and external eating were independently associated with lower BMI; nutrition literacy and emotional eating were not independent predictors. These findings suggest that interventions targeting eating behaviors and body satisfaction may be more effective for promoting healthy body weight in adolescents than strategies focusing solely on nutrition knowledge.