Objective: To explore dietary differences according to socio-economic and sociocultural characteristics of adolescents and young adults.
Design: A systematic review was conducted.
Setting: The main search source was MEDLINE, consulted between January 2012 and March 2017. Quality of selected studies was assessed based on dietary measurement method, sample selection, socio-economic indicator choice and statistical modelling.
Participants: Cross-sectional and longitudinal studies, assessing relationships between socio-economic status and dietary intake (patterns, scores and food groups) in the 10- to 40-year-old general population of high-income countries, were selected.
Results: Among the 7250 reports identified, forty were selected, seventeen of which were of high quality; their conclusions, related only to adolescents, were combined and presented. The most favourable dietary patterns, higher dietary scores, greater consumption of fruits, vegetables and dairy products, and lower consumption of sugary sweetened beverages and energy-dense foods, were associated with better parental socio-economic status, particularly in terms of higher education. Migrant status was associated with plant-based patterns, greater consumption of fruits and vegetables and of sugary sweetened beverages and energy-dense foods. For the other food groups, and for young adults, very few high-quality studies were found.
Conclusions: The socio-economic gradient in adolescent diets requires confirmation by higher-grade studies of a wider set of food groups and must be extended to young adult populations. Future nutritional interventions should involve the most vulnerable adolescent populations, taking account of socio-economic status and migration.
Keywords: Adolescent; Diet; Nutrition; Socio-economic factors; Young adult.