Associations of snack frequency, energy density and nutritional quality with diet quality and cardiometabolic risks in adolescents: National Health and Nutrition Examination Survey 2009–2016

To examine the association between snack characteristics (snack frequency, snack energy density and snack nutritional quality) with diet quality and cardiometabolic risks among US adolescents from the 2009-2016 National Health and Nutrition Examination Survey. Cross-sectional dietary data collected using a 24-h dietary recall from the 2011-2016 National Health and Nutrition Examination Survey (1999 boys and 1897 girls aged 12-19 years) were analysed. Associations between snack characteristics with diet quality, fasting blood glucose, TAG, total cholesterol, HDL, LDL, blood pressure, waist circumference and metabolic syndrome risk score using multiple linear regression were analysed stratified by sex. Higher snack nutritional quality (<i>β</i> (95 % CI): boys 0·31 (0·09, 0·52); girls 0·44 (0·30, 0·57)) was linked to better overall diet quality, whereas snack energy density excluding beverages (<i>β</i> (95 % CI): boys -1·82 (-2·52, -1·12); girls -1·75 (-2·69, -0·82)) was linked to poorer overall diet quality. Among girls, higher snack frequency was associated with lower waist circumference and lower fasting blood glucose (-0·67 (-1·28, -0·05)). Additionally, higher snack energy density and nutritional quality were associated with lower waist circumference and TAG, respectively. No associations between snack characteristics and cardiometabolic indicators or metabolic syndrome risk score were observed for boys. Findings suggest that strategies to improve adolescent snack nutritional quality and energy density may enhance overall diet quality. However, limited associations were observed between snack characteristics and cardiometabolic risk indicators among girls only. Prospective studies are needed to further investigate the relationship between snack characteristics and adolescent health outcomes.