Background Positive wellbeing, including high life-satisfaction can buffer against negative outcomes such as psychological disorders. Modifiable lifestyle factors including diet may be associated with maintaining positive wellbeing however; this association is not extensively researched in adolescents. Fruit and vegetables are markers of healthy diet quality whereas sugar sweetened beverages are markers of poor diet quality. This study investigates whether markers of diet quality are associated with wellbeing in adolescents aged 12–18.

Methods A cross-sectional, nationally representative sample of adolescents aged 12–18 from the Irish, 2014, Health Behaviour in School-aged Children (HBSC) study (n = 8,995). A two-staged sampling strategy was employed, the sampling frame was post-primary schools across Ireland and schools were randomly selected from 8 geographical regions as the primary sampling units. Classes within schools were the secondary sampling units. School and pupil level response rates were 59% and 84.5% respectively. Adolescents self-completed a health and lifestyle questionnaire. Diet was assessed by consumption frequency of fruit, vegetables and soft drinks that contain sugar. Response options were on a 7 point scale ranging from never to everyday more than once (dichotomised as daily vs. less than daily consumption). Adolescents reported general health as good (excellent/good) or poor (fair/poor). Life-satisfaction was assessed on a scale of 0–10 using the Cantril ladder and defined as high (≤7) or low (<7). Separate binary logistic regression models explored associations between dietary variables and general health and life-satisfaction, whilst adjusting for important socio-demographic, lifestyle behaviours and perceived social-support. Stata v.12 was used for analyses.

Results Just over one-quarter of adolescents rated their life-satisfaction as low (26.9% (95% CI: 26.0% to 27.8%) and 13.4% (12.6% to 14.1%) rated their general health as poor. Overall, 39.0% (95% CI: 38.0% to 40.0%) of adolescents reported daily consumption of fruit, 44.7 (43.7% to 45.7%) consumed vegetables and 12.8% (12.1% to 13.5%) consumed soft drinks daily. In fully adjusted models, adolescents who did not eat fruit (OR (95% CI:) 1.35 (1.18 1.54)) or vegetables (1.34 (1.18 1.53)) daily and those who consumed soft drinks daily (1.45 (1.20 1.76)) had a significantly higher odds of reporting low life-satisfaction. Similar associations were observed for poor general health.

Conclusion Consuming a good quality diet is protective of wellbeing. Though this study is cross-sectional, prior longitudinal research found that diet precedes wellbeing. Daily consumption of fruit/veg is worryingly low. Thus creating supportive environments may increase healthy dietary choices which are important for good general health and wellbeing.