Is diet quality changing over time among adults in Canada? An examination using data from 2018 to 2022

Abstract

Background: Poor eating patterns have been established as one of the leading risk factors for chronic disease. Numerous efforts have been made to improve the population’s diet quality, yet the last time dietary intake data were collected at the national level was in 2015, and policies are increasingly based on outdated dietary intake data. Existing data suggest poor diet quality in Canada, with indications of disparities by gender identity, age, income, education, and racial-ethnicity identity, but do not enable assessment of whether diet quality is changing over time. Objective: This research was undertaken to examine trends in diet quality from 2018 to 2022 among adults in Canada overall and among groups characterized by sex, age group, perceived income adequacy, educational attainment, and racial-ethnic identity. Methods: Data were drawn from repeat cross-sectional surveys of adults in Canada from the International Food Policy Study (IFPS) (n=13,448). The Healthy Eating Food Index-2019 (HEFI-2019) was applied to 24-hour dietary recall data to assess alignment of intake with the 2019 Canada’s Food Guide healthy food choices recommendations. Mean HEFI-2019 scores, to a maximum of 80 points, were estimated overall and by sex, age, perceived income adequacy, educational attainment, and racial-ethnic identity. A modified approach to the population ratio method was used to estimate scores adjusted for sociodemographic characteristics. Paired t tests assessed changes in mean scores from year to year and from 2018 to 2022, overall and among subgroups. Results: Among the overall sample, there was weak evidence of a decrease in diet quality from 2018 (46.5) to 2019 (44.0) (mean difference -2.46, SE 1.39, P=0.078) and moderate evidence of an increase in mean total HEFI-2019 scores from 2021 (44.7) to 2022 (48.0) (mean difference 3.30, SE 1.57, P=0.035). However, there was no evidence of a meaningful change in diet quality from 2018 to 2022 (mean difference 1.54, SE 1.5, P=0.305). Variations in total scores from year to year were largely attributable to variations in mean vegetables and fruits component scores. Similar patterns in scores across years were evident among some subgroups. Discussion: The findings point to the need for concerted efforts to improve diet quality among adults in Canada. The introduction of the adjusted population ratio allows future studies to better understand diet quality in particular groups, independent of potential confounding factors.