title: Comparing Prices for Food and Diet Research: The Metric Matters.
abstract: An important issue in research into access to healthy food is how best to compare the price of foods. The appropriate metric for comparison has been debated at length, with proponents variously stating that food prices should be compared in terms of their energy content, their edible mass, or their typical portion size. In this article we assessed the impact of using different food price metrics on the observed difference in price between food groups and categories of healthiness, using United Kingdom consumer price index data for 148 foods and beverages in 2012. We found that the choice of metric had a marked effect on the findings and conclude that this must be decided in advance to suit the reason for comparing food prices.
authors.affiliation: Centre for Diet and Activity Research, MRC Epidemiology Unit, University of Cambridge School of Clinical Medicine, Institute of Metabolic Science, Cambridge Biomedical Campus , Cambridge , UK.
authors.forename: N R V
authors.initials: NR
authors.lastname: Jones
authors.affiliation: Centre for Diet and Activity Research, MRC Epidemiology Unit, University of Cambridge School of Clinical Medicine, Institute of Metabolic Science, Cambridge Biomedical Campus , Cambridge , UK.
authors.forename: P
authors.initials: P
authors.lastname: Monsivais
keywords: Food prices; access; economics; food security; measurement; research methods