Plant-based diets and foods have become increasingly popular in recent years — and for good reason, given the health, environmental, and animal welfare issues surrounding meat, dairy, and eggs. To optimize plant-based advocacy, it’s important to better understand what motivates people to consume fewer animal products. Previous studies have investigated motivations for reducing meat in people’s diets, but less is known about how this plays out with respect to dairy and eggs.

Researchers in the U.K. explored motivations for reducing consumption of meat, dairy, and egg products among three groups of people: omnivores, vegetarians, and vegans. They also studied whether these motivations correlated to a weaker commitment to meat among those who currently eat meat (omnivores) and to dairy and egg products among those who currently eat dairy and eggs (omnivores and vegetarians). In this case, commitment means how attached people are to the use of these products in their daily lives. For instance, a strong commitment means a reluctance to stop eating animal products or a disinterest in replacing them with plant-based alternatives.

The researchers recruited participants using social media platforms. Omnivores, vegetarians, and vegans who were 18 or older with no known eating disorders were invited to complete an online survey. While close to 1,000 people filled it out, a number of respondents ended up being excluded, including those who said they were vegan but had eaten animal products within the last three months, those who said they were vegetarian but had eaten meat within the last three months, and those who didn’t identify as a vegan, vegetarian, or omnivore. The final sample was made up of 237 omnivores, 151 vegetarians, and 377 vegans.

To measure motivation, participants were asked to rate statements like “Plant-based diets are important for my health” and “It does not seem right to exploit animals for dairy products” on a seven-point scale from “not important” to “very important.” Statements fell into three broad categories: environmental statements, health statements, and animal rights statements. Higher scores indicated individuals were more strongly motivated by the category in question.

Similar to motivation, commitment was measured by asking participants to rate statements such as “I cannot imagine substituting dairy products from a meal” and “I cannot imagine substituting meat from a meal” on a seven-point scale from “strongly disagree” to “strongly agree.” Lower scores indicated weaker commitment to eating the animal product in question, suggesting participants would be more likely to adopt a plant-based diet.

What Motivates Omnivores?

For omnivores, the greatest motivation for decreasing consumption of animal products was health. However, it was actually environmental and animal rights concerns that correlated to a weaker commitment to eating meat, dairy, and eggs. More specifically, both of these concerns were linked to lower meat commitment, while environmental motives were linked to lower dairy and egg commitment and animal rights motives were linked to lower dairy commitment.

What Motivates Vegetarians?

Vegetarians were more motivated by animal rights and environmental issues to decrease animal product consumption than omnivores were. Interestingly, though, only animal rights motives were associated with reduced commitment to eating dairy and eggs.

What Motivates Vegans?

Vegans were found to be most motivated by animal rights as the reason for eliminating animal products from their diet. They were more motivated by animal rights than vegetarians, particularly for dairy and egg reduction. Commitment to meat, eggs, and dairy was not studied for vegans, of course, as they don’t eat them.

There were several shortcomings of the study that should be considered. The commitment measures relied on self-assessment rather than tracking actual consumption of animal products by participants. The survey also limited respondents to three main pre-established motivations (health, environmental, and animal rights) and didn’t investigate other potential motives for decreasing animal product consumption such as cultural and religious ones. Lastly, the researchers recruited participants for the study through English-speaking social media groups and networks, so representation was limited to North America and Western Europe. Future studies could include people from other regions and investigate other motivations for diet change.

Overall, the results of this study suggest that the best advocacy strategy for encouraging omnivores to decrease animal product use is to focus on environmental and animal rights arguments, even though their self-stated highest motivation is health-related. For vegetarians, focusing on animal rights arguments is likely to have the strongest effect in reducing dairy and egg consumption.