We appreciate the incredible array of global cuisines available to us. Despite the increasing prices, we enjoy a wide variety of food options, including an abundance of meats that our grandparents could only dream of, given their limited access. However, this diverse culinary landscape comes with a price – the current food choices significantly contribute to carbon emissions and conflict with our climate objectives. Therefore, transitioning towards more eco-friendly diets is crucial.

Instead of imposing strict measures or raising costs, researchers have employed subtle “nudges”, those that gently steer individuals toward socially beneficial choices, to reduce meat consumption. These nudges aim to modify how food choices are presented to consumers without imposing choices on them. Nevertheless, expanding the use of these nudges has proven to be a complex task in general, as it sometimes raises ethical concerns about whether people are fully aware of the messages encouraging them to change their behaviour. In the context of diets which are personal, researchers have argued nudging can be ethically dubious. What business do we have in telling people what to eat?

To address these challenges, a novel approach in behavioral science, known as “nudge+”, can empower individuals to reflect on their choices and encourage meaningful shifts towards more environmentally friendly behaviours. A nudge+ is a combination of a nudge with an encouragement to think. This modification to the nudge allows people to reflect on their choices and decide whether they want to follow a certain nudge or not. For most of us, we have food intentions of doing the right thing, we only need to be made aware of it and then helped to get to that point. The nudge+ does exactly that – once people reveal their goals, the nudge can get them there. It eases compliance to desired behaviours. A nudge+ makes behaviour change more legitimate, ethical and effective. The nudge+ belongs to a wider array of tools that increase behavioural agency. Other prominent tools include educative strategies such as “boosts” which suggest teaching people to develop a better skillset and “thinks” which prompts citizens to engage in group-based deliberation to solve big collective action problems. While nudge+, boosts, and thinks have different operational tactics, they are tied by the unifying goal of empowering citizens.

In this article published recently in Nature Sustainability, we tested our proposition – that human agency improves the effectiveness of behaviour change tools – in an experiment with 3074 UK participants.  We experimentally evaluated three tools aimed at enhancing agency ("boost," "think," and "nudge+") with traditional nudges (opt-out default and labelling) in order to encourage sustainable dietary choices. We designed two conventional nudges: one involved a green default, where participants were automatically placed into a menu featuring eco-friendly options and could opt out if they preferred, and the other was a menu labelled with carbon footprint information using a traffic light system.

Additionally, we created two "boosts." In one, we provided individuals with quick guidelines for adopting a vegetarian diet, and in the other, we had them create conditional "if-then" goal plans. We also introduced a "think" intervention, encouraging people to think critically about their commitment to sustainable eating and then make choices that align with their pledge.

For the "nudge+," we combined the nudge with an element of reflection. There were four nudge+ interventions: in two cases, we merged either the green default or the carbon-labelled nudge with information disclosure to ensure transparency. In the other two, we integrated the "think" component with the green default nudge, allowing individuals to make their sustainability pledge either before or after being defaulted into the green menu. The key distinction with the nudge+ was that it only prompted people to make a pledge without requiring them to deliberate extensively on the best menu choice to fulfil that pledge. Once someone committed to environmentally-friendly eating, the nudge+ automatically guided them into the green menu, making it easier to follow through with their intentions.

Our research indicates that all the behavioral interventions effectively increased intentions to choose sustainable foods, but the most effective results were achieved by promoting reflection on dietary preferences before guiding individuals towards greener diet choices. The addition of a pledge before implementing the default nudge led to a 40% reduction in emissions resulting from intended meal selections.

This study suggests that food companies can enhance their sustainability initiatives by encouraging customers to engage in thoughtful consideration before gently nudging them towards more sustainable food choices. This strategy not only possesses ethical legitimacy but also helps prevent potential resistance from customers who may resist being guided toward a meat-free diet without thoughtful consideration.

As an increasing number of food providers seek ways to promote eco-friendly eating, our nudge+ approach offers a cost-effective means to do so. These brief moments of reflection can be seamlessly integrated into existing platforms, whether online (through food delivery apps) or in-person (such as ordering kiosks). We are optimistic that the practice of thinking before nudging can contribute to the development of more sustainable and enduring shifts in behaviour.