Background: The associations between psychological factors and weight problems in adolescents are not conclusive. We studied associations between psychological factors, including personality and weight problems, in an adolescent population. In addition, we examined the same psychological factors as predictors for change in weight categories during adolescence.
Method: From 1995 to 1997, 8,090 adolescents, aged 13-18 years, participated in the Young-HUNT-I study; of those, 1,619 also participated in a follow-up study in 2000-2001. They completed a questionnaire monitoring eating problems, self-esteem, personality, anxiety, and depression, and had their height and weight measured. Weight problems were defined using the international age-and sex-specific BMI-cut-offs defining underweight, overweight, and obesity. Psychological factors at baseline were studied both in relation to weight categories at baseline, and as predictors for weight change between baseline and the follow-up.
Results: Significant sex differences in mean values were found in all psychological factors, with higher scores in girls compared with boys. In the cross-sectional design, eating problems were associated with weight problems, and the two factors of oral control (EAT-A) and food preoccupation (EAT-B) showed an inverse association. Oral control was associated with underweight, while food preoccupation was associated with overweight and obesity in both sexes. Low self-esteem was associated with overweight and obesity in both sexes, but no association was found between emotional problems or personality traits, and weight problems. During the follow-up, oral control was a clear predictor of weight change during adolescence in both sexes. Oral control protected against unhealthy weight gain but also predicted unhealthy weight reduction in both sexes.
Conclusions: Girls scored higher on all psychological factors compared with boys, but no sex differences were found with regard to the association between psychological factors and weight problems. Eating problems showed the strongest association with weight problems at baseline and were also the strongest predictor of weight change during adolescence.