Behavioural Trials

Introduction

Behavioural Trials fit within the FSA’s research priority of  ‘understanding consumers and our wider society’: In order to implement effective policies, we need to understand how consumers behave, and what influences that behaviour. Behavioural trials are valuable as they robustly and directly measure the impact that an intervention has on consumer behaviour. 

The FSA commissioned five behavioural trials, using experimental and quasi-experimental methods, to understand what affects consumer behaviour across different parts of the food system. This page will be updated as these trials are published. 

Reports

The effect of timers and precommitments on handwashing: a randomised controlled trial in a kitchen laboratory

This study trialled behavioural interventions aimed at improving handwashing behaviour in food handlers in the UK. A three-arm randomised controlled trial in a laboratory kitchen was used to test two interventions, and participants were allocated at random to the groups:

1. Timer group: used a sink with a tap-mounted timer and a poster prompting the correct handwashing technique;
2. Precommitment group: agreed to five statements on complying with specific elements of the FSA’s handwashing guidance before attending the kitchen;
3. Control group: no interventions.

In the kitchen, participants were given a food preparation task that involved handling raw meat. The task included eight points at which participants following official guidance would be expected to wash their hands. Cameras trained on the sinks were used to capture handwashing behaviour.

The trial measured four outcomes:

1. The number of times participants washed their hands;
2. The number of times they washed their hands using soap;
3. The number of times they washed using soap and washed the backs of their hands;
4. The mean duration of handwashing attempts using soap.

The study found that that both the tap-mounted timer and pre-commitment intervention increased the duration of handwashing by around two seconds. However, neither intervention affected frequency or quality of handwashing.

Testing the impact of overt and covert ordering interventions on sustainable consumption choices: a randomised controlled trial

This study investigated whether in an online supermarket displaying products from most to least sustainable, can shift consumer choices towards more sustainable options, compared to when products are randomly ordered. It also examined whether the effect of the ordering intervention differs when the ordering is overt (where information about the ordering is explicit) compared to when it is covert (where participants were not told about the ordering). 

It was an online experiment with a three-arm between-subjects design. Participants took part in an online simulated grocery shopping task and were randomly assigned to one of three groups:  

1. Control: saw randomly ordered products;  
2. Covert: saw products ordered by most to least sustainable and information was not provided on the ordering;  
3. Overt: saw products ordered by most to least sustainable and information was provided on the ordering via a statement shown in a box at the top of each product category page. 

The study found that ordering products by sustainability did not affect product choices (in both the overt and covert conditions). The authors suggest choices may be likely to be predominantly driven by ingrained prior preferences. 

Does proactively asking about allergens before ordering by Food Business Operators (FBO) staff improve customer outcomes?

This research investigated whether proactively asking restaurant customers at point of ordering if they have any food allergies or intolerances improved consumer outcomes, including confidence, comfort, satisfaction and trust. An exploratory objective tested whether it has an impact on declaring an allergy. 

A matched pairs cluster randomised controlled trial was conducted in 18 restaurants of one large national FBO between 28th March 2022 and 30th June 2022. Customers were either in an ‘intervention group’ where they were asked whether they had any food allergies or intolerances before placing their order, or were in the control group.

FBO staff proactively asking customers about their food hypersensitivity at the point of purchase had a positive effect on customers’ confidence that if they needed, they could find out the ingredients in any product at the FBO (for example, if they wanted to avoid an ingredient) and feeling comfortable to ask a member of staff for information about the ingredients in the products they are selling. Proactive asking also had positive effects on customer satisfaction and trust in the FBO. The intervention had a significant effect on the odds of declaring an allergy or intolerance. However, further research would be required to test whether this finding is replicable, as the sample did not include enough customers with self-reported hypersensitivities needed for this exploratory analysis to be sufficiently powered.  

Evaluation of a plant-based meal campaign in workplace cafeterias. An interrupted time series analysis.

In the context of increased sales of plant-based foods over the last few years, this study aimed to identify the impact of an annual plant-based meal campaign- ‘Plant-Forward’- conducted in cafeterias serviced by a large UK catering company. The campaign sought to influence consumer food choices by: 1) increasing the availability of plant-based meals to customers in a workplace cafeteria and 2) making plant-based meals more salient and attractive to consumers by using promotional materials. The evaluation measured two outcomes: the immediate campaign effect of the campaign on the  proportion of plant-based sales (out of total sales) for each week and the estimation of the longer-term effect of the campaign (the decay of the immediate effect over time).

The results of this study indicate that this annual campaign has had a significant positive impact on the sales of both vegan and vegetarian products during the campaign period, aggregating across branches, although its success has differed according to year. 

Consistent with findings of other recent studies, our results suggest that when used in collaboration with promotional material, increasing the availability and salience of vegan and vegetarian items in cafeteria menus can have a pronounced positive impact on sales. Furthermore, given the lack of exploration of the longevity of such effects in the literature, the current study contributes unique new evidence regarding the potential endurance of similar interventions.