Sending direct messages on social media informing people of the negative health and environmental impacts of consuming meat has proven successful at changing eating habits, according to a new study from environmental psychologist Professor Lorraine Whitmarsh.

The research showed that sending direct messages twice a day through Facebook Messenger led to a significant reduction in the amount of red and processed meat participants consumed over a two week / 14-day period.

Participants reported, on average, eating between seven and eight portions of red or processed meat during the previous week before the Facebook messages were sent, which then dropped to between four and five portions during the second week of the intervention and stayed at roughly the same level one month after.

Furthermore, the intervention led to an observed ‘behavioural spillover’ effect in which the participants indicated a desire to also reduce other types of meat they would consume in the future, alongside dairy products.

The study has been published in the journal Frontiers in Psychology.

The health impacts of eating too much red and processed meat are well established, with links to cardiovascular disease, stroke, and certain forms of cancer.

Meat is also a major driver of climate change, responsible for approximately 15% of global anthropogenic greenhouse gas emissions, with a growing consensus among scientists that reducing excess meat consumption is necessary to meet climate targets.

Yet, evidence suggests there is a lack of public awareness of the issue and that people tend to greatly underestimate the extent to which meat consumption leads to climate change.

“With Christmas approaching, it is a good time to consider how much meat we consume on a day-to-day basis and the impacts that this can have on the environment as well as our health,” said Emily Wolstenholme, who led the study.

“Our study shows that making people aware of these climate impacts makes them think about their eating habits. It also shows that people are willing to make changes to help the climate.”

A total of 320 participants were recruited for the study, who were then divided into either one of three experimental conditions, or the control group, and were sent messages through Facebook Messenger twice a day during the two-week intervention period.

Different messages were sent to participants in the experimental groups, each focussing on the environmental and/or health consequences of eating too much meat, for example: 'If you eat only a small amount of red and processed meat, you will protect the environment by reducing the release of harmful greenhouse gases.'

Participants were asked to complete a food diary every day during the two-week period to keep track of their diet.

Surveys were sent to participants at the end of the two-week intervention to measure their red and processed meat consumption, as well as other environmentally-friendly behaviours. The same survey was repeated a month after the end of the intervention.

Over the two-week period the researchers observed a significant reduction in the amount of red and processed meat that was consumed by the participants receiving health messages, environmental messages and combined health and environmental messages – with no significant difference between each of these approaches.

Professor Lorraine Whitmarsh co-author of the study, Director of the Centre for Climate Change and Social Transformations (CAST) and environmental psychologist at the University of Bath, said: "The government’s climate change advisors have told us we need to cut our red meat and dairy consumption by at least 20% by 2030, and our study shows that giving consumers information about the impacts of their food choices is a very simple and effective way of helping achieving this target."

Read more from Lorraine Whitmarsh about another focus area for agriculture and climate change in this new BBC Future Planet feature - Can dairy adapt to climate change?.

Further study information:

Two Birds, One Stone: The Effectiveness of Health and Environmental Messages to Reduce Meat Consumption and Encourage Pro-environmental Behavioral Spillover was published in Front. Psychol., 07 October 2020 |