The Better Food Foundation’s signature strategy, DefaultVeg, leans on the science of behavioral nudges and choice architecture to influence diet shifts. In collaboration with Faunalytics, we present this overview of research addressing the effectiveness of the intervention.
As much as we might like to think otherwise, many of our daily decisions aren’t the result of purposeful thought or deep consideration, but choices that emerge from our habits, psychological biases, and social and physical environments. Nudge theory posits that by changing the choice architecture of our decisions, we can promote better behaviors at a large scale.
In practice, imagine moving all the healthy food to the front of your refrigerator (choice architecture) to hopefully increase the likelihood of reaching for an apple for your midnight snack instead of something you’re trying to avoid. That’s a nudge! This strategy has lots of advantages, but one big one is that it doesn’t remove choice itself (i.e. customers aren’t throwing away all of your junk food overnight) so it’s unlikely to cause much if any grumbling. This represents a powerful opportunity for diet shift—in institutions, nudges can create sustainable dining at scale for every meal, without major pushback from consumers.
Before we jump into the science, let’s define some key terms.
Nudge (or Plant-Based Nudge): As we use the term, a nudge is any subtle way of encouraging a consumer to choose a plant-based option. This can include the format of a menu, the physical space of a food service area, the phrases used by cafeteria staff or waiters, and much more.
Choice Architecture: This psychological term refers to the way choices are presented to people to guide their decisions. For example, when a grocery store places more profitable items at eye level, and less profitable items close to the floor, they structure consumer choice for their own advantage. In a dining setting, choice architecture can refer to menuing, cafeteria design, and food labels, among others, all of which present opportunities for incorporating nudges into the dining experience.
Menu Engineering: When engineering a menu, institutions may make the plant-based option more appealing by changing the placement, description, photos, and more. These are all specific examples of nudges.
Ratios (or Plant-Based Ratios): Food service settings may increase the ratio of veg options to meat options in a menu, as offering a greater variety of plant-based choices tends to result in diners selecting fewer meat dishes.
Plant-based default (PBD): In a PBD, the plant-based option is instilled as the default option with meat available upon request. This is done in various ways, such as restaurants grouping meat dishes on less prominent sections of their menus, cafeterias placing plant-based offerings at the beginning of their buffet lines, or conference registration forms asking people who opt for meat to check a box. You may have also seen the terms “DefaultVeg” (which is an initiative of the Better Food Foundation), or “plant-based by default.”
While developing this overview, Faunalytics spoke to experts currently working on these interventions. Those who promote PBDs have broad motivations, as do stakeholders in dining settings: sustainability, inclusivity towards those with dietary restrictions, animal ethics, or demand (especially from students).
PBDs often, but not always, depend on internal allies—people working in offices or cafeterias who want to be more sustainable, who may or may not follow a plant-based diet themselves. This represents a key advantage of the programs: they have widespread appeal, regardless of individual eating habits.
The research is unequivocal—this is a powerful strategy. Study after study after study shows that centering plant-based foods as the default, or otherwise nudging consumers toward meat-free options, is extremely effective at reducing the amount of meat consumed without significant pushback.
But what about the long term? For example, if a student goes to a plant-based default university cafeteria for four years, are they more likely to reduce meat consumption later in life? If so, plant-based defaults would have an even larger capacity to impact animals and the environment. At this point, we don’t know for sure—but nudges work, in part, because they influence social norms. Since social norms are critical to creating and maintaining preferences for plant-based dining, some behavioral scientists believe PBDs can lead to long-term diet change. More study is needed.
When implementing nudges and defaults, it’s important to recognize that they are much more effective with certain demographics than others. Multiple studies have found that nudges work best for people who are already reducing their meat consumption (flexitarians or reducetarians) or people who are already environmentally or health-conscious. Nudges may also work better on women than men (although this may just be because women are more likely to be flexitarian than men).
One thing that frequently came up in Faunalytics’ conversations with experts currently working on these interventions is that if a PBD isn’t possible for a given institution, other strategies can still influence meal selection. For instance, increasing the number of plant-based options on the menu without making them the default can be an effective strategy. In fact, doubling the amount of vegetarian meals can increase their selection from between 41% and 79% while increasing vegetarian options from 25% to 75% increased their popularity from 12% to 48%. Improving the labels of plant-based meals (discussed in detail below) can also be somewhat effective in promoting individual menu items.
Given that not all stakeholders will be on board with a plant-based default, here is a handy chart to consider what compromises are most ideal.
Since nudges can vary so much, let’s review some findings for some of the most common types of nudge-based situations.
Most PBD programs take place in buffets, dining halls, office cafeterias, or similar food services, and most research on their effectiveness tends to use a conference or university dining hall setting. Experts Faunalytics spoke to tell us that they are especially interested in universities, as influencing younger generations is a key way to shape future dietary norms and (based on anecdotal evidence) universities are usually most open to making these changes.
Instituting a PBD option in dining halls (in which meat was present but had to be specifically requested) was a slam dunk. Across several studies, as shown in the graph below, these programs massively increased the portion of veg meals ordered and eaten: of the well-executed PBDs, the percentage of vegan or vegetarian options jumped from an average of 17.2% to an average of 72.5%, or 55 percentage points—more than quadrupling the baseline percentage! While writing this overview, we were unable to find evidence of an appropriately executed plant-based default program that failed to reduce the amount of meat consumed. In other words, this works.
A few notes: we excluded one study (the Rensselaer trial in the Food for Climate League Study) from this analysis because the implementation of the default was poor: inconsistent signage, prominently displayed meat options, and reports of servers guiding students to choose meat instead of plant-based. With this incorrect implementation, veg orders were ordered at baseline. Secondly, all of these studies were conducted in the U.S. or Europe, and we did not find any research of plant-based default programs in other regions—meaning we don’t yet know if this effect would be the same elsewhere, perhaps especially the Global South.
Like in realty, location is everything in a supermarket. Beyond Meat famously requires that all their products be sold in the meat sections of a supermarket, as opposed to a “vegan” or food allergy section. This decision was likely a wise one—one study found that vegan alternatives sold 67% better in the butcher sections, right next to animal-based meat, as opposed to in their own areas. And placing healthy foods, which could include vegan products, near the check-out counter increased their sales by almost 50%. Location really is key.
But that’s not the only way to influence sales; messaging may help too. One online study moved animal product alternatives to the forefront of the virtual store and added signs about the vegan products’ norms and tastiness (“increasingly chosen” and “try these tasty products”). The researchers saw a 10% bump in veg meat and dairy sales and a 2-3% decrease in animal meat sales. However, the results weren’t statistically significant, so we need more research on supermarket and food retailer messaging to draw stronger conclusions.
PBD programs can also be added to restaurants. One way may be to offer meat as an addition to a plant-based menu item, like a veg burrito you can add chicken to, rather than offering separate veg and chicken burritos. In one online study that tested multiple ways to maximize vegetarian menu items, that strategy won out. For a real-world example, Faunalytics’ case study on a restaurant that implemented a default veg policy for all but one of their breakfast sandwiches found that the veg orders increased by 13% over five years.
Other nudges and labels can still be helpful (look for our advice down below on how to do that). But perhaps the easiest-to-implement change for a restaurant could be to simply get rid of the “vegetarian” or “vegan” section altogether and mix those dishes into the main section of the menu—according to one study, moving the dishes from a “vegetarian” section to the first or last parts of the general menu increased their orders by 56%.
While many people associate vegan options with lower profit margins, instituting a well-planned plant-based default may end up saving money. According to an analysis from the plant-based food options in New York City hospitals (one implemented in collaboration with the Better Food Foundation), the vegan options saved the hospitals about 59 cents per meal by using whole food plant-based ingredients.
All this reduced meat helps the planet—multiple studies confirm that using plant-based defaults reduces the climate impacts of dining halls. One study at Tulane University, Lehigh University, and Rensselaer Polytechnic Institute found the emissions reduction to be about 23.6%, another analysis in New York pegged the number at 36%, and a third at UCLA and Harvard estimated it to be 38.9-42.7%.
Aside from the bottom lines and carbon footprints, these initiatives are often quite popular. In two reports—the New York hospital initiative and a set of experiments in Denmark—plant-based initiatives had an approval rating of 90% among participants. Internal data reviewed by Faunalytics from students at cafes with plant-based defaults shows only a small fraction of students disapprove: just 7%, or one student out of 14. Another study found that across three universities, students’ enjoyment of the plant-based dish increased when it was made the default, surpassing even the meat dishes. And in an online study, participants’ interest in eating out at a restaurant didn’t significantly change when strong plant-based nudges and defaults were added to the menu.
PBD programs help institutions meet climate and other sustainability goals, make their menus more inclusive to everyone—including the estimated 50% of the Latino and Hispanic community, 80% of African Americans and Native Americans, and more than 90% of Asian Americans who are lactose intolerant, as well as people from religions or cultures that restrict on animals products—while improving institutional bottom lines and preserving diner satisfaction. If you work at an institution, organization, or company that serves meals and want to get started, read our blog for tips on how PBDs can be implemented effectively.
*evidence-based blogs or resources, not original research