This study aims to evaluate the efficacy of a healthy diet promotion intervention focused on increasing legume consumption. The intervention is delivered via mobile application in a sample drawn from the healthy adult population.
This study investigates the effects of different communication strategies on behavioral change. The intervention is designed to promote legume consumption. After compiling different profiling and assessment questionnaires, participants watch one of three different possible type of brief video performed by professional actors that discuss the benefits of eating more legumes in terms of health and environmental benefits. Then, with an ad-hoc designed task, they do a simulated grocery shopping and an automatic task to assess approach-avoidance tendency towards meat vs. legumes dishes. Finally, explicit attitudes are assessed. Group differences are explored across three experimental conditions, which vary in the communication strategies. Group 1 watches a video with an educational communicative style and content (EDUCATIONAL), group watches a video presented with a persuasive style, and general content (PERSUASIVE), while group 3 watches a persuasive video with tailored content, based on the profiling phase (TAILORED). The primary aim of the study is to evaluate the impact of these different communication strategies on attitudes and legume purchase. Secondary aims include the investigation of differences in other unspecific purchases.
Study Type
INTERVENTIONAL
Allocation
RANDOMIZED
Purpose
PREVENTION
Masking
DOUBLE
Enrollment
682
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
Participants watch a persuasive video with educational content about the benefits of eating legumes. Then, they perform the grocery shopping simulation
Participants watch a persuasive video with a tailored content about the benefits of eating legumes. Then, they perform the grocery shopping simulation
Piazza dell'Ateneo Nuovo 1
Milan, Italy
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.
Time frame: T1 - day 3. After compiling the baseline assessment (T0) at day 1, participants received the link to complete the second part of the survey at day 3, which was to be completed by the end of the day.
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).
Time frame: T1 - day 3. After compiling the baseline assessment (T0) at day 1, participants received the link to complete the second part of the survey at day 3, which was to be completed by day 3.
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.
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Time frame: T1 - day 3. After compiling the baseline assessment (T0) at day 1, participants received the link to complete the second part of the survey at day 3, which was to be completed by day 3.
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").
Time frame: T1 - day 3. After compiling the baseline assessment (T0) at day 1, participants received the link to complete the second part of the survey at day 3, which was to be completed by day 3.
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.
Time frame: T1 - day 3. After compiling the baseline assessment (T0) at day 1, participants received the link to complete the second part of the survey at day 3, which was to be completed by day 3.