Researchers in the Livestock, Environment and People (LEAP) project at the University of Oxford carried out two natural field experiments and an online randomised trial to investigate the impact of altering the availability of meat alternatives on meal selection. The results contribute to a growing field of evidence around dietary nudges and behaviour change.
Meat production and consumption has detrimental effects on the environment and human health, and the need to promote sustainable diets to protect planetary health is increasingly urgent. Yet most people when faced with a range of options tend to choose meat, whether from habit or social norms. Reducing meat and dairy consumption could lead to substantial benefits for health as well as environmental impacts.
Dr Rachel Pechey, a researcher in the department says: “We know that increasing the availability of lower energy-dense foods can encourage healthier food purchasing but few studies have looked at this effect with meat-free vs meat choices. Our three studies suggest that changing availability of meat-free options could help encourage more sustainable food choices, though further research should look at barriers to chefs implementing such a shift.”
The first study, a natural experiment in one university cafeteria, altered the ratio of meat-free meals from one plant based and two meat to two plant based and one meat over a four month period. Sales data suggests that purchases broadly mapped to the proportion of meat-free meals available: when a third were meat-free, around 40% of purchased meals were meat-free, but when two thirds were meat-free, around 60% of purchased meals were meat-free.
The second study showed a smaller effect: in 18 worksite cafeterias the menu was changed to increase the availability of meat-free meals. Data was analysed for eight weeks before and eight weeks after the menu change. A sensitivity analysis suggested that meat-free sales increased where availability changed, but researchers caution that only around half of chefs took up the new menu options meaning implementation of the experiment was poor, limiting the evidence.
In the third study 2,205 UK adults were recruited to an online trial and divided into three groups. Each were provided four options for main meals, with either 25% meat-free and 75% meat, 50% of each, or 75% meat free and 25% meat choices. Just 12% of individuals chose meat-free when faced with predominantly meat options. Where choices were equal, 28% selected meat free, and where predominantly meat-free options were given, 47.5% of people chose meat-free.
More meat is consumed by those who are more disadvantaged, contributing to inequalities in health. To try to identify interventions that work for everyone and do not increase inequalities, the effectiveness of increasing meat-free availability was examined across different population groups. In this study there was no evidence of different effectiveness.
Overall the results suggest there could be broad effectiveness in increasing meat-free options without creating or exacerbating inequalities. Other research has shown that the environments in which people make their food choices has an impact on their decision, and this work contributes evidence on the effectiveness of dietary nudges.
Dr Pechey says: “We need to find ways to make it easier for people to make more sustainable food choices. In particular, if we all start to cut back on our meat and dairy consumption this could bring important benefits in health and environmental impact. Red and processed meat is a risk factor for non-communicable diseases, and meat is the largest food contributor to greenhouse gas emissions worldwide. Simple changes such as making sure consumers have more plant-based options to choose from could help in achieving these reductions and improving health and environmental outcomes.”
Ruth Francis, Communications Consultant, LEAP Project
Tel: +44 7968 262273; E-mail: firstname.lastname@example.org
The Livestock, Environment and People (LEAP) programme is supported by the Wellcome Trust and a major interdisciplinary research partnership in the areas of global food systems and urbanization. The four year project (2017-2021) is directed by Professor Charles Godfray (Hope Professor and Director of the Oxford Martin School and Future of Food Programme) and Professor Susan Jebb (Professor of Diet and Population Health, Nuffield Department of Primary Care Health Sciences).It is a collaboration between the University of Oxford, the International Food Policy Research Institute (IFPRI), Sainsbury’s and The Nature Conservancy.
Access the paper, published in the International Journal of Behavioral Nutrition and Physical Activity here: