RESUMO
Socio-economic disparities in nutrition have been documented in numerous countries, and have been linked to health inequalities. Social and economic policy changes occurring over the last several years have resulted in growing levels of income inequality in many countries. However, the extent to which these temporal changes have affected nutrition disparities is largely unknown. Our research examined income-related disparities in the nutritional quality of food selections among Canadian households from 1986 to 2001. Data from the 1986, 1992, 1996 and 2001 Family Food Expenditure surveys were pooled together (n=35048). The relationships between household income and the nutritional quality of food purchases (considering nutrients both as absolute amounts and adjusted for energy, and total energy density) were estimated using general linear models, including tests of significance for differences across the survey years. Results revealed significant positive relationships between income and most nutrients, which persisted over time, and for some nutrients grew stronger. One exception was folate, where the positive relationship between income and folate (independent of energy) was no longer apparent in 2001; this could be attributed to the mandatory fortification of some cereal grain products with folic acid, which came into effect in 1998, resulting in greater availability of folate from grain products. There was also a significant negative relationship between income and total energy density (ratio of food energy to food weight), which persisted across the survey years. At a time of growing income inequality and worsening problems of poverty, food policy makers need to pay attention to the potential for policy interventions to exacerbate or improve nutrition disparities.
