High-risk environments for eating foods surplus to requirements: a multilevel analysis of adolescents’ non-core food intake in the National Diet and Nutrition Survey (NDNS)

Objective: Interventions to reduce adolescents’ non-core food intake, i.e. foods high in fat and sugar, could target specific people or specific environments, but the relative importance of environmental contexts vs. individual characteristics is unknown. Design: Cross-sectional. Setting: Data from 4-day food diaries in the UK National Diet and Nutrition Survey (NDNS) 2008-2012 were analysed. NDNS food items were classified as ‘non-core’ based on fat and sugar cut-off points per 100g of food. Linear multilevel models investigated associations between ‘where’ (home, school, etc.) and ‘with whom’ (parents, friends, etc.) eating contexts and non-core food energy (kcal) per eating occasion (EO), adjusting for variables at the EO e.g. time of the day, and adolescent level, e.g. gender. Subjects: Adolescents (n=884) aged 11-18 years. Results: Only 11% of variation in non-core energy intake was attributed to differences between adolescents. In adjusted models, non-core food intake was 151% higher in EOs at ‘Eateries’ (2.51 95% CI 2.14, 2.95) and 88% higher at ‘School’ (1.88 95% CI 1.65, 2.13) compared to ‘Home’. EOs with ‘Friends’ (1.16 95% CI 1.03, 1.31) and ‘Family & friends’ (1.21 95% CI 1.07, 1.37) contained 16-21% more non-core food compared with eating ‘Alone’. At the individual level, total energy intake and BMI, but not social class, gender or age, were weakly associated with more non-core energy intake. Conclusions: Regardless of individual characteristics, adolescents’ non-core food consumption was higher outside of the home, especially at ‘Eateries’. Targeting specific eating contexts, not individuals, may contribute to more effective public health interventions.