Do More Vegan Options Mean More Vegan Orders? The Data Behind Menu Ratios

Want more people to order plant-based? It’s not just about adding vegan options — it’s about changing the ratio.

One of the best ways to increase the uptake of plant-based foods is simple: make them more plentiful. More veggie options, more veggie orders. Easy peasy.

The benefits of ratios are debated by social scientists — a recent study showed that increasing the number of plant-based options on a Chipotle menu barely moved the needle on vegan orders (you can read a write-up of that study in this substack). That’s what inspired my latest deep dive: how does changing the amount of vegan options change the amount of vegan orders?

This is the second post in my series of plant-based nudges — you can read the first one on menu labels here. Now, let’s jump into the science of ratios!

What is the Vegan Sweet Spot?

This intervention isn’t new. Better Food Foundation, an organization I contract with frequently, calls them Climate-Friendly Ratios, while researchers call it “plant-based availability.” To keep it simple, I’ll call this intervention “ratios” in this resource. To understand the overall impacts, I charted all the studies I am aware of that examined plant-based ratios.

As usual, keep in mind that these data come from different studies with different methodologies, participants, dining locations, and types of plant-based meals. Still, the aggregate dataset is illuminating in seeing the bigger picture. To review the full datatable with citations, click here.

The ratio of plant-based foods to orders is highly correlated (r = .76). In other words, as the ratio of plant-based foods to animal-based foods rises, so too do the orders for meatless options. It goes even further: the ratio of plant-based foods explains over half of the variability in plant-based orders (r² = 57.5%)!

The chart’s linear trendline is a good way to predict how many meatless orders you can expect based on the vegan ratio. It could even be reverse-engineered by food services institutions looking to hit a certain quota: if you want half of your orders to be plant-based, you’d need your menu to be about 65% vegan. Just keep in mind this is a rule of thumb, not a foolproof prediction algorithm.

Ratios May Have Other Impacts Beyond Menu Orders

Ratios may also have a normative effect: not only would the higher prevalence of plant-based options increase the plant-based orders in the short-term, but they would also signal to diners that plant-based eating is normal and acceptable in their communities, which could contribute to increased plant-based eating in the long-term. To my knowledge, no study has tested this empirically, but it aligns with existing research on social norms. I think this potential effect would likely be boosted with plant-forward messaging in the dining location or targeted outreach — anything to show that meat reduction is normal and part of the community!

There’s another massive benefit to ratios: universality. I briefly touched on this in my previous post, but many nudges are most likely to work on people who are already flexitarian, climate- or health-conscious, or otherwise inclined towards plant-based foods. According to two studies that examined the demographics of participants, ratios can get all types of people to eat more plants, including certain veg-phobic groups, like men or people who don’t believe in climate change. This represents a significant advantage for the intervention — getting men to consistently eat meat-free has been a tough nut to crack for a while now.

Researchers are also concerned that diners may eat more meat after going to a dining hall that serves predominantly plant-based foods (in research-y terms, we call it behavioral spillover). For example, studies on meatless Mondays and vegan defaults both found that diners were more likely to eat meat later in the day after the intervention. But the only study I could find on ratios that measured behavioral spillover found no effect. While the data is limited, it is optimistic! It doesn’t seem likely that increasing the ratios will cause later meat consumption.

It’s the Ratio that Matters, Not the Number of Options

Keep in mind that I’ve been talking about the ratio of plant-based options to animal-based, not the raw number of vegan options. If you’re working with a restaurant with 50 menu items, going from two plant-based options to four would be just a drop in the bucket. Always think in terms of percentages, not raw values.

There are other factors we need to consider. The Chipotle study I mentioned earlier has a unique feature in its menu design: all the plant-based protein options were part of the same meal —a taco. In other words, none of the plant-based protein options offered anything unique to diners, unlike in other food service institutions, where the plant-based options are their own specific meal. If we present meat-free options as the exclusive way to obtain a specific taste, they’re more likely to be ordered. For example, if a Chinese restaurant only offered Sichuan spices with tofu dishes, then any customer who craved that mala deliciousness would need to order plant-based. Unpublished results from an upcoming study suggest this taste exclusivity does increase plant-based orders. This is a crucial lesson for campaigners: make plant-based options as unique as possible to increase their uptake.

Importantly, we need to ensure plant-based options are fully integrated into the entire menu, not relegated to a separate corner. In one study in a German hospital, listing the vegan option first (both verbally and in writing) nearly doubled their orders. In another study, integrating the plant-based options into a menu and positioning them first and last more than doubled their orders. Ratios won’t work if diners can’t see them.

If campaigners are working to increase plant-based options, they also need to ensure the veggie options are enticing, prominent, and satisfying. As researcher Seth Ariel Green put it, “it helps if it’s yummy.” And please, don’t call them vegan.

Implementing Better Ratios of Plant-Based Options Can Be Tricky, But Worthwhile

It can be hard to imagine profit-oriented institutions like restaurants taking these ideas seriously, but research shows increasing plant-based options isn’t necessarily bad business. In one online study, increasing the number of vegetarian options did not affect customers’ willingness to eat at the restaurant, while another found that in two-thirds of the colleges they examined, increasing vegetarian meal ratios did not reduce the number of students who ate at the dining halls. Another study found that increasing vegetarian meals actually increased participants’ satisfaction with the food. If the intervention is well-implemented, it won’t be intrusive for the diners, either: in one French study, only 5.5% of students noticed an increase in vegetarian options in their local canteen.

As is true with most nudging interventions, the motivations of the food service institution matter quite a bit. The authors of the Chipotle study point out that most studies of plant-based ratios pair an increase of plant-based foods with a decrease of animal-based. This is likely only possible in certain dining institutions that are seeking sustainability, such as university cafeterias or public institutions. A profit-driven corporation is unlikely to remove best-selling meat options from the menu. Therefore, if advocates can only shift the number of plant-based options, not the overall ratio, it might be worth trying a different strategy.

Still, I’m optimistic about increasing the ratios of plant-based to animal-based foods: it’s an exciting intervention that works consistently across all demographics.

Thank you

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