In order to feed the growing global population, we need to transition towards more sustainable, healthier diets. Nutrition and health labelling on foods is now widely implemented, with research showing this approach supports small changes in purchasing and consumption behaviours. Can ecolabels be leveraged in much the same way, to support sustainable shopping choices?
A 2021 systematic review, published in the journal Environment and Behaviour, would suggest so. It posits ecolabels support greater transparency and could help boost demand for more sustainably produced foods.
“Sixty out of 76 interventions that tested the use of a variety of ecolabels reported a positive effect on the selection, purchase or consumption of more environmentally sustainable food and drink products,” the study – the first systematic review and synthesis of evidence in this area – found.
However, the authors noted, an important limitation of the current body of research on ecolabels is that it largely relies on hypothetical experimental designs and does not evaluate actual behaviour in real-life environments.
Since then, a series of studies from the same team have tested the impact of ecolabels in a virtual online supermarket. Results indicated that providing a single environmental impact score (A-E) was effective at decreasing the environmental impact of participants' food purchases. “Compared to control (no labels) there were significant reductions in the [environmental impact scores] when environmental impact labels were presented,” the research team, under lead author Dr Christina Potter of the LEAP project at the University of Oxford, noted.
But, while virtual and physical experience might be merging, a digital supermarket is no substitute for the purchase of food products in the real world. Participants did not spend their money or eat the food they selected.
Bringing ecolabels into a real-world context
To build on this expanding understanding, the University of Oxford researchers decided to take the next step of examining the impact of ecolabels in a real-world context. The latest study, whose first author is Dr Rachel Pechey, undertook a randomised control trail in worksite cafeterias that were allocated to either an ecolabel or control (no label) condition. A total of 111,837 hot meal options were sold during the 31-week period between February and September, split across 15 control sites and 13 intervention sites.
Ecolabel values were generated based on ingredient-level data obtained from the catering provider for each hot menu item sold. Labels show environmental impacts as one of 5 letters (A-E), each with its own colour (from dark green to dark red) representing the lowest to highest environmental impact, analogous to energy-rating schemes.
So, did ecolabels prompt diners to opt for the greener menu item?
It would seem not. The researchers calculated a mean weekly ‘EcoScore’ for the sites that did, and did not, carry environmental labelling.
At the sites where labelling was introduced, the intervention period kicked off at week 15, allowing researchers to chart whether the introduction of ecolabels changed purchasing patterns.
During this initial 15-week baseline period, the mean weekly EcoScore of meals purchased was 67.9 for the control sites and 70.3 for intervention sites. After 15 weeks, when the intervention period commenced, the mean EcoScore was 69.9 for control sites and 71.3 for intervention sites.
“Analysis of the mean weekly EcoScores showed no evidence of an impact of ecolabels, with no significant difference in the change between baseline and intervention period in intervention versus control sites,” they concluded.
What about the impact of access and availability?
However, this doesn’t necessarily mean consumers don’t want to buy more sustainable food products. When the researchers dug down into the EcoScores of the products on sale, they found some challenging trends.
“Around 50% of the mean weekly meals sold had an EcoScore that qualified for an E-rated ecolabel. A similar pattern of results was seen when looking at the meals available (rather than sold)… Hot main meals accounted for 67% of all sales, of these more than 80% would have qualified for an EcoLabel of D or E. The majority of hot sandwiches (93%) and savoury snacks (63%) had an ecolabel rating of E. In contrast, more than 70% of starters and jacket potatoes had an ecolabel of A.”
This suggests that sustainable dietary shifts are unlikely to be achieved through labelling alone. The transition to a lower impact system of food consumption will also rely on access and availability.
“It was apparent that the distribution of EcoScores in the meals offered at the study sites was highly skewed towards high environmental impact options.
“It is possible that ecolabels may be more effective in contexts where there is a greater range of options available for each type of meal. Not only does this make the choice meaningful in terms of environmental impact, but the choice available may reflect established preferences of cafeteria patrons,” Dr Pechey et al suggested.
“There is a continued need to test labels' effectiveness in other real-world contexts, for example, where available options reflect a wider range of more vs. less sustainable options across each type of meal, and in more diverse workplaces. There is also a need to evaluate the wider impact on food provision, rather than just focusing on consumer demand, given that the introduction of ecolabels may increase the availability of lower environmental impact options in the longer-term.”
‘Testing the effectiveness of ecolabels to reduce the environmental impact of food purchases in worksite cafeterias: A randomised controlled trial’
Authors: Rachel Pechey, Paul Batemana, Brian Cooka, Christina Potter, Michael Clark, Cristina Stewart, Carmen Piernas, Susan A.Jebb
'Effects of environmental impact and nutrition labelling on food purchasing: An experimental online supermarket study'
Christina Potter, Rachel Pechey, Brian Cook, Paul Bateman, Cristina Stewart, Kerstin Frie, Michael Clark, Carmen Piernas, Mike Rayner, Susan Jebb
'The effectiveness of environmental sustainability labels on the selection, purchase, or consumption of food and drink products: A systematic review'
Environment and Behavior
C. Potter, A. Bastounis, J. Hartmann-Boyce, C. Stewart, K. Frie, F. Bianchi, et al.