Effect of Meditation on Healthy Food Consumption: A Randomized Controlled Trial

Last registered on September 12, 2024

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Pre-Trial

Trial Information

General Information

Title

Effect of Meditation on Healthy Food Consumption: A Randomized Controlled Trial

RCT ID

AEARCTR-0014296

Initial registration date

September 02, 2024

Initial registration date is when the trial was registered.

It corresponds to when the registration was submitted to the Registry to be reviewed for publication.

First published

September 12, 2024, 5:36 PM EDT

First published corresponds to when the trial was first made public on the Registry after being reviewed.

Locations

Country

United States of America

Region

Arizona

Primary Investigator

Name

Carola Grebitus

Affiliation

Arizona State University

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Other Primary Investigator(s)

PI Name

Nilufer Cetik

PI Affiliation

Arizona State University

Contact Investigator

PI Name

Donna Martens

PI Affiliation

Arizona State University

Contact Investigator

PI Name

Larissa Drescher

PI Affiliation

C3-Team

Contact Investigator

Additional Trial Information

Status

In development

Start date

2024-09-09

End date

2024-10-04

Keywords

Behavior, Health, Lab

Additional Keywords

meditation, stress, food choice, food consumption, randomized controlled trial

JEL code(s)

D91, I12, Q13

Secondary IDs

https://osf.io/pw3f8/

Prior work

This trial does not extend or rely on any prior RCTs.

Abstract

Modern Western societies are challenged by the health risks resulting from poor nutritional behavior. The societal costs of malnutrition are enormous; billions of dollars are spent on direct medical costs for curing physical and mental diseases. The amount attributable to indirect costs, such as deteriorated labor market outcomes, are staggering. Stress-induced dietary choices, characterized by heightened appetite and cravings for high-fat and high-sugar comfort foods, contribute significantly to poor nutrition. Consequently, mitigating stress can potentially enhance the quality of dietary choices.
This research investigates whether mindfulness practices, including breathing techniques and meditation, can influence stress levels and lead to improved food choices. In a laboratory-environment 3-armed randomized controlled trial, we assess the two treatment groups’ responses to meditation by measuring participants’ physiological and perceived stress levels before and after the meditation treatment over a 4-week intervention. Participants’ in an active control group also provides physiological and perceived stress levels before and after interventions over the 4-week period. Real food choices and stated food consumption of both treatment groups and the control group are recorded to investigate the effect of stress and meditation on food decision making.

External Link(s)

Registration Citation

Citation

Cetik, Nilufer et al. 2024. "Effect of Meditation on Healthy Food Consumption: A Randomized Controlled Trial ." AEA RCT Registry. September 12. https://doi.org/10.1257/rct.14296-1.0

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Experimental Details

Interventions

Intervention(s)

This study aims to understand the relationship between stress and food choices/food consumption and whether meditation can be used as a tool for making healthier food choices/leading to healthier food consumption by alleviating stress that an individual experiences in their daily life. The first treatment arm assigns the 10-minute meditation audio recording. The second treatment arm assigns the 20-minute meditation audio recording. The third arm is the active control group who will listen to a different audio recording each week. The participants will come to the lab for the weekly 1-hour sessions for 4 weeks.

Intervention Start Date

2024-09-09

Intervention End Date

2024-10-04

Primary Outcomes

Primary Outcomes (end points)

Food choice, Food consumption, Stress level

Primary Outcomes (explanation)

The main outcome of interest in this study are the (real) food choices of participants that are collected by an unlabeled discrete choice experiment. The participants choose among 2 alternatives with two attributes (food type and prices), for 18 choice tasks (9-pre, 9-post intervention) out of 4 blocks. The attributes include 6 levels for food type (snacks: vegetable, fruit, protein bar, candy bar, chips, string cheese) and 3 levels for price for this experiment.
Another outcome of interest is the food consumption of participants measured by the change in baseline to post-intervention by conducting the Short Form Dietary Questionnaire at the beginning and at the end of the study.

Secondary Outcomes

Secondary Outcomes (end points)

Secondary Outcomes (explanation)

The other outcomes of interest are the change in stress hormones measured by salivary cortisol and change in perceived stress measured by Perceived Stress Scale pre- and post-intervention, and baseline to post-intervention.

Experimental Design

The relationship between meditation and food choices/food consumption will be investigated by conducting a cluster randomized controlled trial with a 3-arm parallel group design. The clusters are defined by the participants who are randomly assigned to a certain treatment arm. The cluster randomization will be done one day before the study starts by following a randomization rule. The study is characterized by a within- and a between-group design.

Experimental Design Details

The study will run over 4 consecutive weeks; consisting of a weekly in-person session at the lab. The first and last sessions will run for approximately 1-hour and the second and third sessions will run for approximately 45-minutes. The lab sessions will be scheduled for before noon, and at the same time and day for each participant. The sessions in a day will randomly be assigned to either one of the treatment or the control conditions. We aim to have an equal number of participants in each study group (1:1:1). The interventions will be conducted by the same, blinded experimenter. The treatment status of any given group will be de-identified by an independent researcher before data analyses to ensure blinding.
The participation incentive is 25 USD in the first week, 15 USD in the second and third week and 45 USD in the last week. The second and the third week’s sessions are expected to run shorter. The differing amounts for the incentives are designed to decrease the study attrition rate. Ultimately, the participants can earn up to 100 USD if they attend all of the 4 sessions. Our invitation and study information will state that our study will investigate food choices and decision making.

Randomization Method

We will randomize 4 units throughout the study by using an online random number generator, a random numbers table and the following rules for each randomization unit defined below.

Randomization Unit

Randomization Unit:
i. The randomization of the clusters into the treatment and control groups will be done by using a random numbers table and the following rule (cite):
Three sessions (A, B, and C) are assigned in the order ABC for digit 1, ACB for digit 2, BAC for digit 3, BCA for digit 4, CAB for digit 5, CBA for digit 6 without replacement, and ignore 0,7-9. The first week’s randomization is going to be the same for the next 4 weeks. The starting (row, column) numbers for the random number table will be determined by an online random number generator.
This way, each weekday will be assigned all the treatment arms but in differing orders. Participants will not know which treatment they are signing up to during the recruitment period. They will only schedule their session’s day and time (i.e., Monday, 9:30-10:30 a.m.) will be expected to stick to that for the next 4 weeks.
ii. Randomization of the discrete food choice experiment blocks and choice sets:
An online random number generator will randomly order the blocks from 1 to 4, and choice sets from 1 to 9. The two of the ordered blocks and the sequence of ordered choice sets will determine the pre- and post-treatment choice sets, for each day during the study.
iii. Randomization of the binding choice set in the post-treatment food choice experiment:
An online random number generator is going to be used to determine the binding choice in a round, and then the binding round in a session. This step is required to make participants actually buy one of their choices and make the experiment a real choice experiment.

Was the treatment clustered?

Yes

Experiment Characteristics

Sample size: planned number of clusters

Three per day, fifteen per week. The clusters are defined by the experimental sessions in a day in our lab.

Sample size: planned number of observations

This study is a fixed size trial. The targeted sample size is 225 participants, 75 for each of the 3-arms (control, treatment 1, treatment 2). The recruitment to the study will continue either until all the spots are filled or, if there are available spots, until the Friday of the first week in the experiment. No new participants will be admitted to the study after the first week. The lab has a maximum capacity of 18 participants. We expect a 30% attrition rate.

Sample size (or number of clusters) by treatment arms

75 in treatments 1 and 2 each and 75 in the control.

Minimum detectable effect size for main outcomes (accounting for sample design and clustering)

We are interested in conducting a 3-arm parallel design randomized controlled trial with multiple observations. Our aim is to capture the change in true mean responses of participants in their real food choices measured by the unlabeled discrete choice experiment. The comparison will be made with a significance level of α=0.05 to achieve a power of 80% (β=0.20). We are assuming that the standard deviation within each group is σ=3.5, and the minimum detectable effect size for main outcomes Δ2=1.5.

Supporting Documents and Materials

IRB