It’s a classic example of what behavioural scientists have known for decades: people don’t make choices like rational economists. We are, as neuroscientist Antonio Damasio famously put it, ‘feeling machines that think.’
When it comes to food, those feelings are a powerful influence on what we eat, in addition to other less ‘rational’ aspects of our inner psychology. Habit, identity, personality and even simple cues in our environment can influence our food choices more than a carbon number, however stark, ever could.
Nudging Sustainable Meals
But we know dietary change is possible; we simply need to get smarter about how we encourage change. Enter behavioural science.
Over the past decade, a wave of research has shown that small tweaks to the way that food is presented, described and served can make a surprisingly big difference, and often without anyone feeling forced or deprived. These techniques, sometimes called “nudges”, work with human psychology rather than against it. Not only are many proven to be effective across a range of robust research trials, but they are typically easy to do, low-cost, and highly acceptable to the public.
Take the example of menu engineering. When restaurants make vegetarian dishes the default - requiring customers to actively ‘opt-in’ to ask the server for meat – the shifts we see in ordering behaviour are dramatic. In one Dutch study, switching the default sandwich from chicken to beans boosted plant-based orders from under 10% to almost 80%. Crucially, meat was still available to diners; it just required a little extra effort to find.
And even more minimal changes work too. Offering a greater variety of plant-based dishes increases their uptake, as does serving slightly smaller portions of meat while bulking out the plate with vegetables. In trials, these modest shifts didn’t dent satisfaction, and diners rarely noticed the difference to their meals.
The order of items also matters. On food delivery apps, placing lower-carbon restaurants, and the meals they are serving, at the top of lists or menus led to a relative reduction in carbon emissions per order of around 12%. Repositioning plant-based products next to meat in supermarket aisles has also helped to boost their sales by around 9%, by making them more visible to customers who might never otherwise wander across their usual display in the dedicated ‘Vegetarian Section’.
Language is another powerful lever. As accumulating evidence now shows, calling something ‘vegan’ or ‘vegetarian’ often backfires, evoking ideas of restriction, tastelessness or moralising. But describe the same dish as “rich and creamy” or “smoky and indulgent,” and people lean in. Research is increasingly indicating that if you do wish to signal that a menu item is meat-free, then ‘plant-based’ is the most appealing way to do so – it’s terminology that is seen as healthier, tastier, and more natural than either ‘vegan’ or ‘vegetarian’, and significantly boosts purchases as a result.
Even better, label plant-based products as ‘high protein’ with a punchy percentage claim, and see sales bulk up.
What Works for Whom?
Many behavioural techniques work reliably across populations because they tap into universal, often unconscious aspects of human psychology - mechanisms largely unaffected by culture or local norms.
But, we can go further. By tweaking language and messaging, in particular, to reflect the identities, beliefs, and values of different audiences, we can often make these interventions even more effective.
For example, people who see meat as a symbol of strength and power, and who strongly align their personal identity to these traits, may react very differently to ‘reduce meat, choose plants’ messaging than those who view food as an opportunity for sensory exploration, pleasure or keeping their body pure. Gender plays a particularly strong role in this regard, with men tending to be more responsive to protein-focused claims and pushing back more strongly against meat-free messaging, while women are more receptive to naturalness food cues, and may be more neophobic toward unfamiliar meats and novel alt-protein products.
Recent research also challenges one commonly held assumption - that vegetarians are more likely to be receptive to ethical and benevolent messaging than meat-eaters. In a study of 500 US participants, for example, vegetarians were found to place significantly less importance on the value of benevolence, while endorsing stimulation, achievement, and power more strongly, while meat-eaters leaned more towards self-direction and security. The takeaway here is that, while vegetarian and meat-eating audiences do hold different sets of values that we must consider when tailoring our messaging, these do not always align to our pre-existing assumptions about what will work for whom. As always, more behavioural science research is needed.
The next frontier, then, isn’t about more information overload, but harnessing a varied range of behaviour change techniques from our wider toolbox, and exploring ways to personalise these strategies so we can deliver the right tactics and messages to the right audiences at the right time.