A MONASH University and Deakin University research partnership with Ritchies IGA supermarkets has prompted shoppers to buy more vegetables by introducing “nutritional serve pricing”, a new way of presenting cost that shows the price of a standard serve alongside the usual per-kilogram figure.
The National evaluation of nutritional serve pricing report found the initiative increased average daily vegetable purchases by more than 60 grams among all loyalty card shoppers. At a store level, daily vegetable purchase volumes rose by 7.5 kilograms.
The results come as most Australians fall well short of recommended vegetable intake. The latest Australian Bureau of Statistics data shows only 6.5 per cent of adults meet the recommended daily intake.
To help address the gap, researchers introduced “nutritional serve pricing”, which displays a per-serve price based on a 75-gram nutritional serve, consistent with the Australian Dietary Guidelines. The aim is to give shoppers a clearer, more intuitive sense of value at the point of purchase.
For example, carrots priced at $2.99 per kilogram are shown as costing about 22 cents per 75-gram serve, a framing designed to highlight affordability and simplify budgeting decisions.
The approach was rolled out across more than 70 Ritchies IGA supermarkets in March 2024.
Researchers analysed 850 consecutive days of de-identified loyalty card data to compare fruit and vegetable purchases before and after the launch, making it the largest real-world Australian assessment of pricing communication for vegetables.
The main analyses focused on 56 stores that traded across the full period to control for disruptions such as openings and renovations.
Monash Business School consumer psychology expert and project lead Associate Professor Fiona Newton said the findings reflected purchasing patterns rather than confirmed consumption, but showed a clear behavioural shift after per-serve pricing was introduced.
“Vegetable consumption in Australia remains far below recommended levels, and many families feel that healthier choices are less affordable,” she said.
Deakin University marketing professor Josh Newton said the partnership created a rare opportunity to study behaviour in a natural retail setting, with gains occurring without promotional activity.
Ritchies IGA chief executive Fred Harrison said supermarkets could play a direct role in making healthy choices simpler for families.
The initiative has also been endorsed by AUSVEG, with chief executive Michael Coote calling it a practical, research-backed tool to lift consumption as part of the Plus One Serve program.
