Feasibility of a Healthy Trolley Index to assess dietary quality of the household food supply

Abstract

Supermarket receipts have the potential to provide prospective, objective information about the household food supply. The aim of this study was to develop an index to estimate population diet quality using food purchase data. Supermarket receipt data of 1 month were available for 836 adults from a corporate office of a large retail chain. Participants were aged 19-65 years (mean 37·6 (SD 9·3) years), 56 % were female and 63 % were overweight or obese. A scoring system (Healthy Trolley Index (HETI)) was developed to compare food expenditure with the Australian Guide to Healthy Eating. Monthly expenditure per food group, as a proportion of total food expenditure, was compared with food group recommendations, and a HETI score was calculated to estimate overall compliance with guidelines. Participants spent the greatest proportion on discretionary foods, which are high in fat/sugar (34·8 %), followed by meat including beef and chicken (17·0 %), fresh and frozen vegetables (13·5 %) and dairy foods (11·3 %). The average HETI score ranged from 22·6 to 93·1 (out of 100, mean 58·8 (SD 10·9)). There was a stepwise decrease in expenditure on discretionary foods by increasing HETI quintile, whereas expenditure on fruit and vegetables increased with HETI quintile (P < 0·001). The HETI score was lower in obese compared with normal-weight participants (55·9 v. 60·3; P < 0·01). Obese participants spent more on discretionary foods (38·3 v. 32·7 %; P < 0·01) and less on fruits and vegetables (19·3 v. 22·2 %; P < 0·01). The HETI may be a useful tool to describe supermarket purchasing patterns and quality of the household food supply with application for consumer feedback to assist improved quality of foods purchased.Key words: Diet quality: Supermarkets: Food supply Poor eating habits are one of the key drivers of overconsumption of energy, weight gain and obesity. Australians consume inadequate amounts of fruit, vegetables and whole grains and, on average, get about 35 % of their energy from energy-dense, nutrient-poor discretionary food and beverage items (1,2) . As a result, improving the food supply to support healthy food choices has been identified as a priority for Australian health promotion efforts and internationally (3,4) .About 60 % of Australian food retail expenditure is in the supermarket, indicating its potential as a key setting to influence the food supply (5) . Previously, supermarket purchases have been found to relate to dietary intakes, particularly at the household level (6,7) . For example, when compared with 4 d of weighed food record data, 1 month of shopping purchase information produced reasonable estimates about energy and fat intake (7) . Many nutrition interventions promoting the purchase of healthier foods have been trialled in the supermarket setting. Although the evidence is equivocal for the effectiveness of supermarket interventions focused on point-of-purchase dietary education and information provision (8,9) , the potential for success using an innovative approach in this setting has ...

Development of the Healthy Purchase Index (HPI): a scoring system to assess the nutritional quality of household food purchases

“…Guide to Healthy Eating (43) . The HPI, by design, has the advantage of directly accounting for food group and subgroup expenditure shares without needing information on the weight and nutritional composition of the foods.…”

“…However, the cultural acceptability of such theoretical baskets has been questioned ( 42 ) . In 2015, the Healthy Trolley Index – in which daily servings of food groups (as a percentage of the total recommended daily serving) were simply translated into the proportion of monthly expenditure per food group – was developed by an Australian research team to compare food expenditure with the Australian Guide to Healthy Eating ( 43 ) . The HPI, by design, has the advantage of directly accounting for food group and subgroup expenditure shares without needing information on the weight and nutritional composition of the foods.…”

“…The HPI thus overcomes the fact that proportion by weight does not necessarily align with proportion by price, as some food groups are more expensive than others ( 44 ) . This food price hierarchy was ignored in the Australian Healthy Trolley Index ( 43 ) , which did not take into account that fruit, vegetables and meat provide more costly kilojoules than starches and fats ( 3 ) .…”

“…The HPI thus overcomes the fact that proportion by weight does not necessarily align with proportion by price, as some food groups are more expensive than others (44) . This food price hierarchy was ignored in the Australian Healthy Trolley Index (43) , which did not take into account that fruit, vegetables and meat provide more costly kilojoules than starches and fats (3) . To be consistent with many dietary guidelines that emphasize the importance of increasing both diversity and quality to achieve a healthy balanced diet (45)(46)(47) , the HPI included two sub-scores: the purchase diversity sub-score and the purchase quality sub-score.…”

Estimating Dietary Intake from Grocery Purchase Data - A Comparative Validation of Relevant Indicators

“…An additional key aspect is mapping electronic shopping history to study participants through loyalty cards for example (Ni Mhurchu et al, 2007, 2010; Taylor et al, 2015;. Validity of dietary intake assessed through purchase data is mostly tested with common epidemiological individual dietary intake methods, i.e.…”