Interaction effects of socio-economic position in the association between eating location and diet quality in Portuguese children and adolescents: results from the National Food, Nutrition and Physical Activity Survey 2015–2016

Abstract

This study aims to evaluate the interaction effect of socioeconomic environment (SEE) in the relationship between the eating location (EL) and diet quality, in children and adolescents. Data included children and adolescents (3-17y) from a National Dietary Survey Sample (IAN-AF 2015/2016, n=987). Dietary intake was obtained by 2-day food diaries (children) or 2-24-hour-recall (adolescents). Participants were classified into four groups of EL: “Home”, “Other homes”, “School” and “Restaurants”. Diet quality was measured as a higher adherence to a healthy eating pattern. A previous developed socioeconomic classification was used, and participants were grouped as belonging to a low socioeconomic environment (LSE) or middle-high socioeconomic environment (MHSE). Linear regression models were used to evaluate the association between EL and diet quality, stratified by the SEE. One-quarter of participants was classified in the “Home” group, 14% in “Other homes”, 17% in “Restaurants” and 45% in “School”. A statistically significant interaction effect was found (p<0.01) for the SEE in the association between eating location and diet quality. After adjustment for potential confounders, in LSE, children and adolescents belonging to “Other homes” (β̂=−2.07; 95%CI:−3.70;−0.44) and “Restaurants” (β̂=−3.31; 95%CI:−5.08;−1.54) had lower scores in the diet quality score, comparing to “Home”. In MHSE, comparing to “Home”, “Restaurants” showed lower diet quality (β̂=−1.56; 95%CI:−2.65;−0.48), while the “School” had better diet quality (β̂=0.90; 95%CI:0.16;1.64). The SEE influences the association between EL and diet quality and, belonging to more disadvantaged SEE, might represent a higher risk of unhealthy eating habits when eating out-of-home compared to when eating at home.