The role of socio-economic position as a moderator of children's healthy food intake

Children of low socio-economic position (SEP) consume poorer diets than those of high SEP; however, there is limited understanding of why socio-economic gradients in diet occur. Some evidence suggests that determinants of dietary intake may differ between SEP groups. The aim of the present study was to determine whether the associations between personal and environmental variables and children's fruit and vegetable intake, and healthy dietary behaviours are moderated by SEP. A total of 395 children aged 9 to 13 years and their parents were recruited in Adelaide, South Australia. Personal and environmental dietary predictors were measured using child-completed online questionnaires and telephone interviews with parents. Dietary intake was measured using an online FFQ. First, dietary predictors were identified using correlated component regression, and subsequently tested for moderation by four SEP indicators using partial least-squares structural equation modelling. Fruit and vegetable intake and healthy behaviours were predicted by self-efficacy, attitudes and a supportive home environment. For girls, only the associations of self-efficacy with healthy behaviours were moderated by occupation. For boys, income moderated the associations of fruit and vegetable intake with attitudes, and healthy behaviours with supportive home environments. Occupation and employment moderated the associations of boys' family environments and fruit intake, and attitudes with healthy behaviours. Reducing socio-economic disparities in children's healthy dietary intake may be more successfully achieved by tailoring health promotion policies and interventions according to variables that moderate the relationships between dietary intake and SEP.