Association between dietary factors and health-related quality of life in adolescents longitudinally over three years from age 11-16 years

BackgroundCross-sectional studies have linked adolescent food choices to health-related quality of life (HRQoL). This research sought to determine the degree to which adolescent food choices are linked to HRQoL longitudinally.MethodsData were collected in the UK as part of the Wellbeing in Schools (WiSe) survey. Adolescents (N = 2241) (49% female, n = 1112) were surveyed at age 11-12 (2014); 13-14 (2016); and 15-16 years (2018). HRQoL was assessed using the Kidscreen10 and food intake using a 17-item short food frequency questionnaire (sFFQ). Confirmatory factor analysis of FFQ responses indicated five food factors (junk food; fruit and vegetables; bread and dairy; meat; protein). Using a bidirectional strategy the five food factors and HRQoL were examined at three points in time over a period of six years. This cross-lagged model was examined using a multigroup strategy to assess the stability of responses over time in boys and girls, thus accounting for temporal stability of the different constructs.ResultsBoys reported higher HRQoL than girls at age 13-14 and 15-16 years. Boys consumed 'protein' and 'meat intake' more frequently at all time-points. Girls reported more frequent consumption of 'fruit and vegetables' at all time points, while boys' intake decreased progressively at ages 13-14 and 15-16 years. Cross-lagged panel modelling indicated that more frequent intake of 'fruit and vegetables', and 'protein' was associated with lower HRQoL scores at baseline (age 11-12 years) and that this association strengthened through ages 13-14 and 15-16 years. Lower HRQoL scores at baseline were associated with more frequent 'bread and dairy' intake at age 13-14 years but not at 15-16 years. No associations were observed over time between HRQoL and 'junk food' or 'meat intake'.ConclusionsThese findings imply the importance of diet to quality of life during adolescence. Further research is required to understand why certain dietary factors were associated with lower HRQOL over the course of adolescence. Meanwhile, intervention to enhance HRQoL should target girls while efforts to enhance 'fruit and vegetable' intake should target boys.