Table 2 Selected simple indicators for measuring the relative availability of healthy versus unhealthy foods in supermarkets

1

fresh and frozen fruit and vegetables (including packaged) vs. soft drinks, crisps and snacks, sweet biscuits, cakes and slices, confectionery

Based on food categories used in previous studies by Farley et al 2009 [38], Rose et al 2009 [23], Miller 2012 [24], and Bodor et al 2013 [39]. These studies did include canned fruit and vegetables but these were not included in the ‘gold standard’ in this study, so excluded.

2

fresh fruit and vegetables (including packaged) vs. soft drinks and energy drinks

These food groups represent the most commonly included healthy and unhealthy food categories in previous research on food availability in-store

3

fresh fruit and vegetables (including packaged) vs. soft drinks, crisps and snacks, confectionery

The food groups in this indicator are those used in the Australian study by Cameron et al 2013 [40]. Fresh fruit and vegetables were used by 15 previous studies as the only healthy food items measured. Soft drinks, crisps, and confectionery were the three most commonly measured unhealthy foods in previous studies.

4

fresh and frozen fruit and vegetables (including packaged) vs. soft drinks, energy drinks, crisps and snacks, sweet biscuits, confectionery

Similar to indicator 1 but excludes the cakes and slices to improve feasibility of measurements in-store.

5

frozen fruit and vegetables vs. soft drinks, energy drinks, crisps and snacks

The included food categories were all common inclusions as healthy or unhealthy foods in previous studies. Excludes fresh fruit and vegetables as these products require more complex measurements to be performed in-store (e.g. measuring bins, no clear shelves).