Do healthy diets cost more? A critical re-examination of diet cost methodology and its association with dietary adequacy

Abstract

This dissertation aimed to critically re-examine diet cost methodology, including the derivation of diet costs, and how diet costs predict dietary adequacy among Canadians. First, a systematic scoping review was conducted to examine the state-of-art in diet cost methodology and measures. Second, diet cost methodology was applied to match 2015 Canadian Community Healthy Survey-Nutrition data feasibly to the Canadian Consumer Price Index (CPI). Third, a population-level comparison of three diet cost methods using a consistent dietary assessment method, and varying type, quantity, and geographic coverage of food prices through use of three CPI price lists was conducted. Fourth, the association between daily diet costs and dietary adequacy was investigated in Canada. Methodological refinement in diet costing is needed to appropriately monitor diet costs in Canada. Further research is needed to understand the food purchasing motivations by diet cost to disentangle consumer preferences and diet adequacy in relation to diet costs.