Meat-eaters who abstain to take part in Veganuary are more likely to think that meat is disgusting after giving it up for the month, researchers have found.

Studies by psychologists at the University of Exeter also found that some people identify less as meat-eaters after trying to avoid animal products during January.

The findings suggest that people’s beliefs around their diets are likely to follow their actions and may have implications for people hoping to change other behaviours, such as those giving up alcohol for dry January.

“Normally, the idea is to educate people first to change their attitudes, and hopefully they end up changing their behaviour,” said Natalia Lawrence, an associate professor of psychology at the University of Exeter. “But if you persuade people to change their behaviour for a month, it seems that these things follow.”

Veganuary began in 2014 after Jane Land and her partner, Matthew Glover, came up with the idea following the success of Movember, which Glover had taken part in. Since then, plant-based foods have become mainstream, with National Trust members voting last month that at least half of the food on menus at its 300 cafes should be plant-based.

Lawrence, working with PhD researcher Sophie Hearn and others at Exeter, has conducted a number of studies into Veganuary, funded by the Medical Research Council.

A study in Frontiers in Nutrition journal tracked 40 participants to measure meat disgust before and after they took part in the abstinence month, finding that although most participants lapsed back into eating meat, those who reduced their meat consumption the most were more likely to have greater disgust for meat afterwards.

Surveys of 46 Veganuary participants last year, published in Appetite, a scientific journal, found they were significantly less likely to say they identified as a meat-eater.

“We know that identity strongly shapes food choices, so by encouraging participants to view themselves as individuals who reduce or avoid meat, Veganuary may pave the way for lasting, positive changes in dietary habits,” Hearn said.

The likely psychological mechanism is that people are unconsciously trying to resolve a cognitive dissonance between a behaviour – taking part in Veganuary – and a belief – that they enjoy eating meat.

There are other cognitive dissonances around meat-eating that people avoid through defensive rationalisations, Lawrence said. “Most people think it’s wrong to be cruel to animals, and [large amounts] of meat in the UK is produced in factory farms, which something like 75% of UK adults agree should be banned,” she said. “So most people are not acting in line with their values when they’re eating meat.

“But what research suggests is that they either avoid thinking about it, or they tell themselves that the animals were well treated, or that you have to eat meat to be healthy.”

Campaigns such as Veganuary can be effective because they persuade people to temporarily lower their defences, Lawrence said. “Because they’re no longer eating meat during that month, they don’t need to be avoiding thinking about it.”

Similar effects may change people’s attitudes to alcohol and socialising during dry January. Negative attitudes towards alcohol-free drinks, or beliefs that social occasions require people to drink alcohol, may be undermined by a temporary change in behaviour.

The Exeter team is planning a further round of research looking at both dry January and Veganuary in the new year.

“We want to test some strategies to help people deal with barriers they might face,” Hearn said. Some participants will be given strategies to try, compared to a control group who take part as normal.

Toni Vernelli, Veganuary’s head of communications, said the organisation was pleased to see that Exeter’s research backed up its own participant surveys.

“At the end of their Veganuary pledge, more than 80% of participants tell us they plan to permanently reduce their meat and dairy consumption by at least 50%.

“This finding has been consistent for the past five years. Our participants report the same top challenges too – dealing with friends and family and eating out. We’re very excited to support Exeter University with new research investigating protocols for tackling these barriers.”