---
title: "Ecological momentary assessment of stress during a 6‑month behavioral weight loss program: study p"
id: "plos-one-17-intensive-longitudinal-assessment-of-stress-and-stress-related-concepts-across"
canonical_url: "https://medichelpline.com/clinical-feed/plos-one-17-intensive-longitudinal-assessment-of-stress-and-stress-related-concepts-across"
content_type: "clinical_feed_article"
specialty: "General"
source_name: "PLOS ONE (Medicine)"
source_url: "https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0357572"
published_at: "2026-09-10T14:00:00.000Z"
evidence_level: "Journal Feed"
license: "CC-BY-NC-4.0 / Informational Use"
---
# Ecological momentary assessment of stress during a 6‑month behavioral weight loss program: study p
## Provenance & Clinical Metadata
- **Canonical URL:** https://medichelpline.com/clinical-feed/plos-one-17-intensive-longitudinal-assessment-of-stress-and-stress-related-concepts-across
- **Specialty:** [General](https://medichelpline.com/clinical-feed/general.md)
- **Primary Source:** PLOS ONE (Medicine)
- **Source URL:** [Original Journal Publication](https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0357572)
- **Published At:** 2026-09-10T14:00:00.000Z
- **Evidence Rating:** Journal Feed
## Executive GIST (TL;DR)
- This protocol describes the INSTANT prospective observational cohort that uses intensive longitudinal smartphone-based **ecological momentary assessment (EMA)** to measure daily stress, coping, affect, and related behaviors during a community-based behavioral weight loss program. - The study will enroll approximately 50 adults with obesity (BMI ≥ 30 kg/m2) who are newly enrolled in local community weight management programs; participants must own a smartphone and agree to install the study app. - Data collection includes four in-person study visits (baseline/week-0, week-6, week-12, week-26) with height, weight, and questionnaires on chronic stress, coping, and weight-related behaviors. - At each measurement wave participants will complete at least 14 days of EMA: one morning survey, four signal-contingent surveys in fixed 3-hour windows, and one nighttime survey each day via smartphone. - During EMA periods participants will also wear devices to assess physical activity and sleep and collect waking saliva samples for cortisol assay; device-based metrics include MVPA and ENMO-derived activity estimates. - The primary exposure is early-program variability (difference) in signal-contingent stress, coping, and affect. The primary outcome is weight change across 6 months; secondary outcomes include physical activity and sleep. - Hypotheses: higher variability in daily stress will associate with less weight loss and lower physical activity and sleep (Hypotheses 1a/1b); higher variability in coping and positive affect will relate to less weight loss (Hypothesis 2). - The study was IRB-approved May 2024, registered at ClinicalTrials.gov (NCT06668259) in October 2024; startup began March 2024, recruitment began March 2025, and anticipated completion in early 2027. - Findings are intended to inform whether real-time adaptive interventions (ecological momentary interventions, EMI) targeting stress and coping during weight loss could support behavior change and improve outcomes. - No analytic data are yet available; data will be shared upon study completion. Funding is from NIGMS (P20GM144269); one author has an industry advisory role disclosed.
## Clinical Analysis & Structured Key Points
Intensive longitudinal assessment of stress and stress-related concepts across a weight loss program: Protocol for a longitudinal ecological momentary assessment study | PLOS One Browse Subject Areas ? Click through the PLOS taxonomy to find articles in your field. For more information about PLOS Subject Areas, click here . Article Authors Metrics Comments Media Coverage Reader Comments Figures Figures Abstract Background Fluctuations in daily stress and the inability to cope with this stress (i.e., coping) can negatively impact behavior and potentially weight loss. Longitudinal studies using ecological momentary assessment (EMA) of psychological factors and behavior may inform interventions that can be adapted in real-time to modify stress and stress-related factors to enhance weight loss. This study’s purpose is to examine variability in stress and stress-related concepts and weight loss during a behavioral weight loss program with the intent of this informing future interventions. Methods Individuals with obesity (body mass index: ≥ 30 kg/m 2 ) who are newly enrolled in an existing community-based behavioral weight loss programs will be recruited. Participants will complete four visits, to coincide with before program (week-0), early program (6-weeks), program mid-point (3-months), and program end (6-months). Each visit will include height, weight, and questionnaires related to chronic stress and coping, and weight-related behaviors. Participants will then complete at least 14-days of EMA, including one morning survey, four signal-contingent surveys during fixed 3-hour windows, and one night-time survey daily via a smartphone application. During these 14-days, participants will also complete device-based measures for physical activity and sleep and waking saliva collection to evaluate cortisol. The primary exposure is the difference (i.e., variability) in signal-contingent survey stress, coping, and affect at baseline. The primary outcome is weight change across 6-months. This study received initial startup in March 2024, and was registered in Clinical Trials in October 2024. The study began recruitment in March 2025 and anticipate completion in early 2027. Discussion Findings may inform justification for the pursuit of an ecological momentary intervention focused on improving stress while engaging in a behavioral weight loss intervention to support behavior change and potentially weight loss. Trial registration ClinicalTrials.gov NCT06668259 Citation: Kracht CL, Davis AM, Apte U, Snodgrass M, Collier TY, Honas JJ, et al. (2026) Intensive longitudinal assessment of stress and stress-related concepts across a weight loss program: Protocol for a longitudinal ecological momentary assessment study. PLoS One 21(9): e0357572. https://doi.org/10.1371/journal.pone.0357572 Editor: John W. Apolzan, Pennington Biomedical Research Center, UNITED STATES OF AMERICA Received: February 2, 2026; Accepted: August 17, 2026; Published: September 10, 2026 Copyright: © 2026 Kracht et al. This is an open access article distributed under the terms of the Creative Commons Attribution License , which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. Data Availability: No datasets were generated or analysed during the current study. All relevant data from this study will be made available upon study completion. Funding: CLK and this work was supported by the National Institute of General Medical Sciences [ https://www.nih.gov/ , P20GM144269]. The content is solely the responsibility of the authors and does not necessarily represent the official views of the NIH. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript. Competing interests: Dr. Jakicic serves on the Scientific Advisory Board for Wondr Health, Inc. There are no other competing interests among the authors. Abbreviations: BMI, Body Mass Index; ELISA, Enzyme-linked immunosorbent assay; ENMO, Euclidian Norm Minus One; FCI, Food Cravings Inventory; FDA, Federal Drug Administration; EMA, Ecological Momentary Assessment; EMI, Ecological Momentary Intervention; MVPA, moderate-to-vigorous physical activity; PANAS, Positive and Negative Affect Scale Introduction By 2030, over 50% of adults will have obesity based on current population-based trends [ 1 ]. Obesity prevalence can be reduced by individual-focused lifestyle interventions as these programs are generally effective at helping people lose weight [ 2 , 3 ]. However, some people who engage in these interventions lose less weight than others [ 4 ]. This difference in weight loss may be influenced by psychological factors, such as perceived stress, that play a key role in behavior change [ 4 ]. Intensive longitudinal assessment of these psychological factors and daily behavior can inform the design of adaptive interventions that can intervene in real-time to change stress and thereby behavior, improving weight loss success. Fluctuations in daily stress and inability to cope with stress (i.e., coping) can negatively impact behavior, thus weight loss [ 5 ]. However, successfully assessing this relationship on the day-to-day level has been difficult. Ecological momentary assessment (EMA) methodology can address this limitation by assessing the antecedent ( what happened before the behavior ), the behavior, and the consequence ( what happened after the behavior ) pathway, thus evaluating the temporality of state and behavior. Accordingly, EMA methodology includes sending short surveys [ 6 ], via mobile application on phone (mHealth), on psychological measures and behavior context. Studies using EMA methodology found that momentary stress and related health constructs (e.g., affect) are correlated with cortisol levels [ 7 ] and other health parameters (e.g., blood pressure) [ 8 ]. These findings were demonstrated in an EMA study amongst 143 children (ages 8–12 years), where morning self-reported stress was negatively associated with same day moderate-to-vigorous physical activity (MVPA), but not salivary cortisol collected after wakening [ 9 ]. In addition to stress, a person’s affect (i.e., emotion and mood) may also impact their ability to be active thus lose weight. In a systematic review of EMA studies ( n = 12), positive affect predicted subsequent physical activity, but not negative affect [ 10 ]. Therefore, one’s higher perceived stress, lower coping, and lower positive affect may hinder physical activity [ 10 ], lead to poor eating behaviors [ 11 ], and limit weight loss. Investigating daily psychological factors and obesity-related behaviors using EMA across a weight loss intervention may inform creation of an adaptive intervention. Data collected from EMA methodologies can lead to adaptive mHealth interventions, including ecological momentary interventions (EMI) which provide in-the-moment support based on self-report or device feedback to prevent behavior relapse [ 12 ]. One possible option where EMA may be used to promote behavior change is physical activity. Engaging in physical activity can be used to cope with stress, suggesting an EMI could propose physical activity amongst low coping times, and promote weight loss [ 13 ]. Investigating these claims while an individual is undergoing behavior change (i.e., weight loss) may help identify if these behaviors are valuable focus points for future adaptive weight loss interventions. Objective and aims The overarching aim of this study is to elucidate potential pathways of stress and stress-related concepts with subsequent health behaviors during a behavioral weight loss intervention. The primary exposure is the difference (i.e., variability) in signal-contingent survey stress, coping, and affect early in the program. The primary outcome is weight change across a behavioral weight loss program, and secondary outcomes are physical activity and sleep. We hypothesize that high variability in daily stress will be related to less weight loss across the initial (12-weeks) and full (26-weeks) program (Hypothesis 1a). Our second hypothesis is that high variability in daily stress will be related to less physical activity and sleep across the initial and full program (Hypothesis 1b). These hypotheses were constructed as higher variability and fluctuations aligns with past literature that with individuals who experience lower stressful daily events and who are able to cope consistently and easily with this daily stress may be more active and lose more weight compared to individuals experience daily changes in stress and are less able to cope or find it difficult to do so [ 5 , 14 ]. Finally, we hypothesize that high variability in coping and positive affect will be related to less weight lost across the initial and full program (Hypothesis 2). Methods Study design The current study, intensive longitudinal assessment of stress and stress-related behaviors across a behavioral intervention or INSTANT , is a prospective observational cohort of individuals enrolled in a community-based weight loss program. The University of Kansas Medical Center Institutional Review Board (IRB) approved this study in May 2024 (IRB#:00160436) and registered with ClinicalTrials.gov in October 2024 (NCT06668259). The current protocol follows the reporting guidelines for EMA studies (See S1 Table ). This study was approved by the local IRB prior to study implementation, and in compliance with US Federal Regulations and local IRB policies, this study undergoes annual IRB review with an extension provided on at least an annual basis. Participants, eligibility, and recruitment This study seeks 50 individuals who are newly enrolled in a community-based weight loss program centered in a metropolitan area of a Midwest state. Participants will be recruited from an existing 6-month-long community-based weight management program hosted by the University of Kansas Medical Center, local Diabetes Prevention Programs and other behavioral weight loss programs in the local area that may range from 6 to 12-months long. These weight management programs typically include trained health educators, 1-hour weekly video meetings, group peer support, structured nutrition plan (low calorie diet), personalized activity recommendations, and behavior change modifications [ 15 ]. Prospective participants will be recruited at their initial consultation or orientation visit for their behavioral weight loss program. Flyers will also be presented to participants at their initial visit. Measures were planned to coincide with initial enrollment (week-0), early weight change (week-6), and later weight change measures (week-12, week-26). To be included, participants must be newly enrolled or plan to enroll in a community-based weight management program, must be over 18 years of age, have body mass index (BMI) ≥30 m/kg 2 , own a smartphone and be willing to download the mobile application to receive text messages [ 16 ]. Participants who chose to cease their community-based weight management program involvement after enrolling in the INSTANT study can still participate in later assessments, improving upon past studies which only included individuals who completed their program [ 17 , 18 ]. Indeed, stress may impact continued engagement in a weight management program. Participants will be excluded for being currently prescribed FDA-approved medications for weight loss, treatment for a medical condition that could affect body weight, or impacting stress levels (e.g., antidepressants), a current psychological condition that is untreated, hospitalization for a psychological condition within the past 12-months, or not being on a stable dose of treatment for at least 6-months. Other exclusion criteria are not being fluent in writing or speaking the English language, mobility limitations so they are unable to perform physical activity, and a family member who was previously enrolled or is currently enrolled in the study. Procedures Screening. Interested participants will complete a web screening tool using a secure online platform [ 19 ]. If a participant qualifies but is not currently enrolled in a community-based weight loss program, staff will provide them with local options so they are able to enroll and meet inclusion criteria. Potential participants who met screening criteria will be contacted for an initial phone call, during which a trained staff member will inquire about the participant’s ability to travel to visits, wear an accelerometer on their wrist, complete a salivary cortisol kit and EMA surveys related to stress and sleep patterns as well provide their health history and current medication usage. Eligible individuals will be scheduled for their baseline visit (week-0). Baseline (week-0). In the first visit, written consent will be obtained from the participant prior to performing study procedures. Height and weight will be assessed by a trained staff member. The participant will complete questionnaires and will be fitted with an accelerometer to wear for 14-days. Participants will also be provided a 5-day salivary cortisol kits. The procedures for collecting, storing and transporting the saliva samples will be explained by trained staff in additional to the participant watching a short tutorial on the collection process and provided with written instruction. Participants will have the EMA app downloaded to their phone, and receive a tutorial on the app. Beginning the next day after the baseline visits, the participant will respond to EMA prompts for 14-consecutive days and wear the accelerometer. After 14-days, participants will return their accelerometer and saliva kit and delete the EMA app off their phone. Follow-up visits (week-6, week-12, week-26). At Visit 2–4, participants will have their height and weight measured, complete questionnaires, be provided the 5-day salivary cortisol collection kit, have an accelerometer fitted to their wrist to wear for 14 days and have the EMA app reinstalled on their phone to conduct the same EMA questions for 14-days. To reduce questionnaire burden in follow up visits, participants were given the option to complete questionnaires 1-week ahead of the visit using an online tool (REDCap). Harms and adverse events will be assessed at each visit. Study assessments are low-risk, thus we anticipate few study-related harms. Measures As shown in Fig 1 , momentary stress, demographics, attendance, stress and related concepts, health behaviors, and weight will be collected across this study. Download: PNG larger image TIFF original image Fig 1. Schedule of enrollment, and assessments during study. https://doi.org/10.1371/journal.pone.0357572.g001 Ecological momentary assessment (EMA). Participant’s current state and behaviors will be collected using a customizable software (LifePak, LifeData Corporation, Marion, IN). This software is compatible with both Apple and Android iOS delivered phone notifications as reminders, and study surveys will be completed within the app. Questions occur in the same order for all surveys and are provided as supplementary material ( S2 – S4 Tables ) and a detailed account of constructs is provided in Fig 1 . Participants will receive six surveys, including four signal-contingent and two fixed surveys (i.e., available for a fixed time period), through the app each day for 14 continuous days as performed by others measuring physical activity [ 20 ]. Signal-contingent surveys occurred randomly within fixed 3-hour windows (8:00am–11:00am, 11:00am-2:00 pm, 2:00 pm-5:00 pm, and 5:00–8:00 pm) and expire 45 minutes after the initial reminder. The two fixed surveys include the morning and evening survey; the morning survey will be available for four hours (8:00am-12:00 pm), and three hours for the evening survey (5:00–8:00 pm). These schedules may be shifted for non-traditional schedules, such as shift work, to ensure participants are available to answer these questions during their waking hours. Participants will be provided with three reminders for signal-contingent surveys, including the initial reminder, and reminders at 15-minutes and 30-minutes, if necessary. Participants will be sent reminders for the morning and evening surveys every hour, if necessary. Sampling time frames and prompt strategies were informed by past EMA studies [ 21 , 22 ]. Participants will be expected to complete at least one morning survey and two within-day surveys (~50%) for 5-days [ 23 ], with an additional incentive for 7-days in a row as conducted in our preliminary EMA studies. Primary exposures. Variability in stress and coping: In the morning survey, morning stress and coping will be assessed using questions based on the Daily Health Diary as assessed in past EMA studies [ 23 , 24 ], their own current stress and their perceived ability to cope with stress. Participants will be prompted to indicate the current stress, with response options ranging from 0–10 and 10 indicating higher stress. Participant coping will be queried with a similar question on their ability to manage stress right now, with the same response options and a higher score indicating a higher ability to manage stress. Variability in affect: During signal-contingent surveys, participants will answer a set of five brief questions including positive and negative affective response. Then, participants will complete 5-questions based on how they are currently feeling positive and negative affect based on the Positive and Negative Affect Scale (PANAS), a validated scale which has been adapted in other EMA studies of affect [ 10 , 24 , 25 ]. These questions will be asked in the same order and are based on previous EMA studies [ 6 , 23 , 26 ], with response options ranging 1–4, with higher indicating more prevalent feelings of the emotion. An average of the two positive affect questions and three negative affect questions will be calculated. The average positive affect score will be compared for variability in affect. Other stress-related states, and health behaviors. As shown in Table 1 , morning, signal-contingent, and evening surveys will assess other relevant considerations. The morning survey includes 16 questions, ending with the two questions that assess stress and coping. Participants will be asked, based on the previous night, how many hours of actual sleep they received, their bedtime and wake-time, and overall sleep quality. These questions are adapted from the Pittsburgh Sleep Quality Index, which is validated in adults [ 27 ]. This is followed by two questions on accelerometer and saliva compliance and then questions related to coping with stress and cravings the previous day. Cravings will be assessed using an adapted momentary scale of the Food Cravings Inventory (FCI). The FCI is questionnaire queries five different subscales including high fat foods, sweets, carbohydrates/starches, fast foods, and fruits and vegetables; this scale has been validated in adults [ 28 ]. FCI responses are via a 5-point scale, with higher scores indicating more frequent cravings. In the momentary question, we will ask how often they felt cravings for each of the 5-main items, with similar Likert scale responses. For example, they will be asked how frequent they craved carbohydrates/starches during the day. They will be asked if they indulged in cravings, and if so, which of the five craving groups with check box option. Download: PNG larger image TIFF original image Table 1. Daily Schedule of Ecological Momentary Assessment Surveys sent to participants for 14-days. https://doi.org/10.1371/journal.pone.0357572.t001 The signal contingent survey includes eight questions total. First, participants will be asked a 1-question item to assess routine and disorder within the moment adapted from the Confusion, Hubbub and Order Scale [ 29 ]. Then, participants will complete the PANAS scale as described previously.
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