Inequities in diet quality are evident worldwide and reflect structural disadvantages. There is increasing evidence that dietary inequities may be most meaningful in relation to educational attainment, a finding that contradicts the common belief that dietary inequities are primarily attributable to material disadvantage (i.e., inadequate incomes). Moreover, diet quality declines with each step down the educational ladder, and therefore these educational inequities affect all of society. The purpose of this Perspective is to posit that educational attainment is a key structural stratifier of diet quality and dietary inequities-what we term a super determinant-and that greater research attention should be given to interrogating pathways through which educational attainment shapes diet quality. To inform our Perspective, we conducted extensive keyword searches in PubMed and Google Scholar to identify concepts, theory and empirical data pertaining to educational inequities in diet quality, health and mortality, followed by a conceptual synthesis of findings. Based on these findings, we first describe pathways through which educational attainment shapes diet quality. We then demonstrate that educational inequities in diet quality are often much larger than they are for income. For instance, absolute gaps and gradients in Healthy Eating Index-2015 scores between the most and least educated adults were 7-11 points in Canada, whereas they were just 2-5 points in relation to household income. We provide converging evidence related to large and growing educational inequities in diet quality, health and mortality internationally. We subsequently consider an important counterfactual-that the affordability of a healthy diet is the key determinant of dietary inequities-and empirically demonstrate that economic factors are not primary drivers of socioeconomic inequities in diet quality. We conclude that attributing dietary inequities primarily to the higher costs of healthy foods is overly simplistic and ignores the critical role of educational attainment as a structural stratifier of dietary inequities.
Olstad et al. (Thu,) studied this question.