Objective: To determine the reliability of streamlined data-gathering techniques for examining the price and affordability of a healthy (recommended) and unhealthy (current) diet. We additionally estimated the price and affordability of diets across socio-economic areas and quantified the influence of different pricing scenarios.
Design: Following the Healthy Diets Australian Standardised Affordability and Pricing (ASAP) protocol, we compared a cross-sectional sample of food and beverage pricing data collected using online data and phone calls (lower-resource streamlined techniques) with data collected in-store from the same retailers.
Setting: Food and beverage prices were collected from major supermarkets, fast food and alcohol retailers in eight conveniently sampled areas in Victoria, Australia (n 72 stores), stratified by area-level deprivation and remoteness.
Participants: This study did not involve human participants.
Results: The biweekly price of a healthy diet was on average 21 % cheaper ($596) than an unhealthy diet ($721) for a four-person family using the streamlined techniques, which was comparable with estimates using in-store data (healthy: $594, unhealthy: $731). The diet price differential did not vary considerably across geographical areas (range: 18-23 %). Both diets were estimated to be unaffordable for families living on indicative low disposable household incomes and below the poverty line. The inclusion of generic brands notably reduced the prices of healthy and unhealthy diets (≥20 %), rendering both affordable against indicative low disposable household incomes. Inclusion of discounted prices marginally reduced diet prices (3 %).
Conclusions: Streamlined data-gathering techniques are a reliable method for regular, flexible and widespread monitoring of the price and affordability of population diets in areas where supermarkets have an online presence.
Keywords: Food affordability; Food price; Nutrition policy; Obesity prevention; Online data; Pricing policies.