Background
Increased soft drink consumption has been proposed as both predictor and result of mental health problems. Although possible mechanisms for both directions have been suggested, understanding of the association is limited. Most previous research has been cross-sectional and could not assess directionality.
Method
This study investigated the directionality of the association between soft drink consumption and mental health using longitudinal panel data of 5882 children and adolescents from the nationally representative German KiGGS baseline study (2003–2006) and KiGGS Wave 1 (2009–2012). Soft drink consumption and mental health problems were assessed by standardized questionnaire (baseline) and telephone interview (Wave 1). Four cross-lagged panel models were specified and compared regarding their fit indices. Specific paths were tested for significance.
Results
Positive cross-sectional associations between soft drink consumption and mental health problems were found at both measurement points (ps < .01), even after controlling for third variables (including age, gender, and socioeconomic status). Only the lagged effect of mental health problems on soft drink consumption reached statistical significance (β = 0.031, p = .020), but not the effect in the opposite direction. The corresponding model also showed the best model fit overall.
Conclusions
Mental health problems predicted soft drink consumption over an average of six years, but not vice versa. These findings suggest that consuming soft drinks might be a dysfunctional strategy of coping with mental health problems for children and adolescents and highlight the importance of considering mental health problems in the prevention of soft drink overconsumption and obesity.
