Altering the default order in which foods are shown on screen, or offering substitutes lower in saturated fat could help customers make healthier choices when shopping for food online, according to a study supported by the NIHR Oxford Biomedical Research Centre.
The authors, from the University of Oxford’s Nuffield Department of Primary Care Health Sciences, say this is the first randomised trial to directly compare interventions targeting the environment and the individual to encourage healthier food choices.
The findings, published in the open access International Journal of Behavioral Nutrition and Physical Activity, could provide effective strategies to improve the nutritional quality of online food purchases.
The lead author of the study, Dr Dimitrios Koutoukidis, said: “Finding effective ways of lowering the saturated fat in our shopping baskets, such as from meat, cheese, or desserts, may translate to eating less of it, which could help lower our risk for heart disease.”
Dr Koutoukidis and his team conducted an experiment with 1,088 grocery shoppers from UK households, using an experimental online supermarket specifically designed for the study. Participants were asked to select ten ‘everyday’ foods that they and their household would want to eat, from a pre-specified shopping list.
Participants were randomly allocated to one of four groups: The first group was shown a list of food products ranked according to their saturated fat content from low to high (environmental-level intervention); the second group was offered the option to swap a product high in saturated fat for a similar one with lower saturated fat (individual-level intervention); the third was shown a combination of both the ranked list and offered the option to swap products (combined intervention); the fourth group was shown neither a ranked list, nor given the option to swap products (no intervention control).
The authors found that participants in any of the intervention groups chose products with less saturated fat than those who received no intervention. Altering the default order was more effective than offering product swaps. Combining the two was more effective than offering swaps but no more effective than altering the default order of items.
For participants who received no intervention, the percentage of calories from saturated fat in their shopping baskets was 25.7%. Altering the order of foods or offering swaps reduced the percentage calories from saturated fat by 5.0% and 2.0%, respectively. A combination of both interventions reduced it by 5.4% compared to controls.
The total cost of the shopping basket did not differ significantly between groups.
The authors caution that these interventions now need to be tested in real online supermarkets, as this was an experimental platform where participants chose but did not receive the food and did not spend their own money.
As the pre-specified shopping list focused on foods high in saturated fat, the effect of these interventions would likely be smaller during real-life shopping which would include a broader range of products.
Dr Koutoukidis said: “These results could be capitalised by online supermarkets which could implement either or both strategies knowing that they are potentially effective for lowering the saturated fat in their customers’ shopping baskets and thus shape heathier food choices.”