Add a Legume to Your Cart

Experimentální: Educational

Participants watch a video with an educational content and communicative style about the benefits of eating legumes

Jiný: Educational

Participants watch an educational video about the benefits of eating legumes. Then, they perform the grocery shopping simulation and the automatic task for approach/avoidance assessment

Experimentální: Persuasive

Participants watch a video with an educational content and a persuasive communicative style about the benefits of eating legumes

Jiný: Persuasive

Participants watch a persuasive video with educational content about the benefits of eating legumes. Then, they perform the grocery shopping simulation

Experimentální: Tailored

Participants watch a video with a persuasive communicative style and tailored content about the benefits of eating legumes

Jiný: Tailored

Participants watch a persuasive video with a tailored content about the benefits of eating legumes. Then, they perform the grocery shopping simulation

Portions of purchased legumes - task 1 - simulation on online grocery shopping

In the first task, specifically designed for the present study, participants are asked to complete a simulated online grocery shopping for the following week. The task is structured to closely resemble a real shopping experience: each item can be added to the virtual cart in a potentially unlimited number of units, with higher values indicating larger quantities purchased and a value of zero indicating that the item was not selected.

The primary outcome will consist of the total number of legume-based items selected, subsequently converted into servings. This conversion process will be carried out by the nutrition research team.

Explicit attitudes about legumes

Participants were asked to express their opinions about legumes using six different bipolar scales, introduced with the following instruction:

"Now think about legumes (e.g., chickpeas, peas, beans, lentils, broad beans). Which adjectives do you consider most appropriate to describe them? Please respond to each pair of adjectives without overthinking your answer."

The bipolar adjective pairs were as follows: negative-positive; bland-tasty; isolating-convivial; unsatisfying-satiating; difficult-easy; loser-winner.

Responses were recorded on 7-point scales ranging from 1 (indicating the negative pole of each adjective pair) to 7 (indicating the positive pole of each adjective pair).

Swipe Approach-Avoidance Task (SwipeAAT)

The Swipe Approach-Avoidance Task (SwipeAAT) is a smartphone-based version of the Approach-Avoidance Task, in which participants interact with visual stimuli according to specific instructions. Stimuli must either be "approached" (by swiping upward) or "avoided" (by swiping downward) depending on the instructions provided. Reaction times recorded during task performance are analyzed to infer spontaneous behavioral tendencies of approach or avoidance toward the presented stimuli.

To assess spontaneous approach and avoidance tendencies toward legumes and meat, two scores were computed for each participant:

Legume SwipeAAT score, calculated as the difference between the mean of all valid latencies (see Data Exclusion) for the "Avoid legumes" trials and the "Approach legumes" trials.

Meat SwipeAAT score, calculated as the difference between the mean of all valid latencies (see Data Exclusion) for the "Avoid meat" trials and the "Approach meat" trials.

Intention to increase legumes portions in the future - single ad hoc item

Participants were asked to report their future intention to increase their weekly consumption of legumes using a single-item measure ("Do you intend to increase your consumption of legumes in the near future?"). Responses were provided on a 5-point scale ranging from 1 ("absolutely not") to 5 ("absolutely yes").

Portions of other purchased items - task 1 - simulation on online grocery shopping

In addition to legumes, purchases made during the online grocery shopping simulation task will also be analyzed for other categories of interest, including meat, fruit and vegetables, processed foods, and related product categories.