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 v. individual characteristics is unknown.
Design: Cross-sectional.
Setting: Data from 4d 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 day) and adolescent level (e.g. gender).ParticipantsAdolescents (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 (ratio; 95 % CI) in EO at 'Eateries' (2·51; 2·14, 2·95) and 88 % higher at 'School' (1·88; 1·65, 2·13) compared with 'Home'. EO with 'Friends' (1·16; CI 1·03, 1·31) and 'Family & friends' (1·21; 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 the home, especially at eateries. Targeting specific eating contexts, not individuals, may contribute to more effective public health interventions.
Keywords: Adolescents; Eating context; Ecological momentary assessment; Multilevel models; Non-core food.