Simplifying Diet Tracking in a Digital Weight Loss Intervention

Simplifying Dietary Self-Monitoring in a Digital Weight Loss Intervention

The purpose of this study is to compare two approaches for tracking dietary intake in a 12-month fully digital weight loss intervention: (1) Simplified approach: track Red Zone Foods (e.g., foods high in calories and low in nutritional value) vs. (2) Detailed approach: track all foods and their corresponding calories. In essence, this is a head-to-head comparison of two tracking approaches; the investigators are evaluating whether weight loss is comparable over 12 months, or whether one approach will have greater weight loss.

The investigators will recruit 328 adults. Broadly, adults with overweight or obesity who live in the United States will be eligible. The weight loss intervention will last 12 months. All participants will be asked to track their dietary intake + body weight + steps daily as well as complete weekly behavioral lessons and action plans to promote healthy eating and physical activity. All study tasks will occur remotely. Assessment of body weight and survey measures will occur at the beginning of the trial ("baseline"), and at 1, 6, 12, and 18 months.

Study Overview

• Status: Not yet recruiting
• Conditions: Obesity; Overweight; Weight Loss; Health Behavior; Lifestyle Intervention
• Intervention / Treatment: Behavioral: Simplified Dietary Self-Monitoring; Behavioral: Core Behavioral Weight Loss Intervention; Behavioral: Detailed Dietary Self-Monitoring

• Study Type: Interventional
• Enrollment (Estimated): 328
• Phase: Not Applicable

Contacts and Locations

• Study Contact: Name: Study Team; Phone Number: 650-549-7047; Email: mlp9@stanford.edu

Study Locations

• United States
  • California
    • Palo Alto, California, United States, 94304
      • Stanford University School of Medicine

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult; Older Adult
• Accepts Healthy Volunteers: No

Description

Inclusion Criteria:

• adults (ages 18+ years)
• body mass index (BMI) 25.0 to 45.0 kg/m^2
• smartphone ownership
• willing to install a mobile app on personal smartphone
• access to a personal email account
• English or Spanish language proficiency
• interest in losing weight through behavioral strategies
• living in the United States
• willing to be randomized

Exclusion Criteria:

• concurrent enrollment in another weight management intervention
• loss of ≥5% weight in the past 6 months
• prior or planned bariatric surgery during the trial period
• current or planned pregnancy during the trial period, or recent pregnancy in the past 6 months
• currently breastfeeding or lactating
• current use of anti-obesity medications
• living with someone else participating in the study
• hospitalization for a mental health condition in the past 12 months
• inability to engage in moderate forms of physical activity akin to brisk walking
• medical or psychiatric contraindication (e.g., end stage renal disease, cancer, schizophrenia, dementia, use of steroids, use of antipsychotic medication)
• if an individual would be better suited for a more intensive or different type of intervention based on a health condition (e.g., individuals with history of an eating disorder or cardiovascular event, uncontrolled hypertension, or uncontrolled diabetes mellitus)
• investigator discretion for safety reasons

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Treatment
• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: Double

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: Simplified (Track Red Zone Foods); Simplified + Core	Behavioral: Simplified Dietary Self-Monitoring; Participants randomized to receive this intervention are instructed to track their Red Zone Foods (i.e., foods high in calories and low in nutritional value) daily via a web-based checklist. Participants receive a daily Red Zone Food goal.; Behavioral: Core Behavioral Weight Loss Intervention; All participants receive a 12-month core behavioral weight loss intervention consisting of the following: goal setting; daily self-monitoring of body weight & steps; weekly behavioral lessons and action plans to promote healthy eating and physical activity; and tailored feedback. The intervention will be delivered remotely via email and/or text message.
Experimental: Detailed (Track All Foods/Calories); Detailed + Core	Behavioral: Core Behavioral Weight Loss Intervention; All participants receive a 12-month core behavioral weight loss intervention consisting of the following: goal setting; daily self-monitoring of body weight & steps; weekly behavioral lessons and action plans to promote healthy eating and physical activity; and tailored feedback. The intervention will be delivered remotely via email and/or text message.; Behavioral: Detailed Dietary Self-Monitoring; Participants randomized to receive this intervention are instructed to track all foods/drinks and their corresponding calories daily via a mobile app. Participants receive a daily calorie goal.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Weight Change from Baseline to 12 Months	mean change in body weight (kg); assessed objectively via e-scale using standardized procedures (e.g., place the scale on a hard surface; collect weight in the morning, without clothing, prior to eating/drinking)	Baseline, 12 Months

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Weight Change from Baseline to 1 Month	mean change in body weight (kg); assessed objectively via e-scale using standardized procedures	Baseline, 1 Month
Weight Change from Baseline to 6 Months	mean change in body weight (kg); assessed objectively via e-scale using standardized procedures	Baseline, 6 Months
Weight Change from Baseline to 18 Months	mean change in body weight (kg); assessed objectively via e-scale using standardized procedures	Baseline, 18 Months
Caloric Intake Change from Baseline to 12 Months	mean change in daily caloric intake (kilocalories); assessed via the Automated Self-Administered 24-Hour Dietary Assessment Tool (ASA24): 2 separate diet recalls per time point: 1 week day, 1 weekend day	Baseline, 12 Months
Diet Quality Change from Baseline to 12 Months	mean change in diet quality; assessed via the Healthy Eating Index, calculated from ASA24 data; score range: 0 to 100, with higher scores indicating better diet quality	Baseline, 12 Months
Step Count Change from Baseline to 12 Months	mean change in step count; assessed objectively via activity tracker	Baseline, 12 Months
Health-Related Quality of Life (Physical Health) Change from Baseline to 12 Months	mean change in health-related quality of life (Physical Component Summary); assessed via the SF-36 survey; score range: 0 to 100, with higher scores indicating better quality of life	Baseline, 12 Months
Health-Related Quality of Life (Mental Health) Change from Baseline to 12 Months	mean change in health-related quality of life (Mental Component Summary); assessed via the SF-36 survey; score range: 0 to 100, with higher scores indicating better quality of life	Baseline, 12 Months
Engagement in Self-Monitoring Dietary Intake	operationalized as average percentage of days in the 12-month intervention of self-monitoring dietary intake (Red Zone Foods for Simplified arm vs. all foods/calories for Detailed arm); assessed via e-checklist for Simplified arm and via app for Detailed arm; will report median (IQR) if data are non-normally distributed	daily during the 12-month intervention
Engagement in Self-Monitoring Weight	operationalized as average percentage of days in the 12-month intervention of self-monitoring body weight; assessed via e-scale; will report median (IQR) if data are non-normally distributed	daily during the 12-month intervention
Engagement in Self-Monitoring Steps	operationalized as average percentage of days in the 12-month intervention of self-monitoring steps; assessed via activity tracker; will report median (IQR) if data are non-normally distributed	daily during the 12-month intervention

Collaborators and Investigators

• Sponsor: Stanford University
• Investigators: Principal Investigator: Michele L. Patel, PhD, Stanford University

Study record dates

Study Major Dates

• Study Start (Estimated): May 1, 2027
• Primary Completion (Estimated): April 30, 2030
• Study Completion (Estimated): October 31, 2030

Study Registration Dates

• First Submitted: May 14, 2026
• First Submitted That Met QC Criteria: May 14, 2026
• First Posted (Actual): May 22, 2026

Study Record Updates

• Last Update Posted (Actual): May 28, 2026
• Last Update Submitted That Met QC Criteria: May 22, 2026
• Last Verified: May 1, 2026

More Information

Terms related to this study

• Keywords: behavioral intervention; obesity; overweight; mobile health; obesity treatment; RCT; intervention; weight loss; digital health; self-monitoring; diet; weight management; digital intervention; BMI; body weight; randomized clinical trial; adults; comparative effectiveness; lifestyle; non-inferiority; behavior change; obesity management; weight reduction; weight loss intervention; remote intervention; tracking; noninferiority trial; track; standalone intervention; self-monitor; red zone foods; calorie counting; comparative effectiveness trial; standalone
• Additional Relevant MeSH Terms: Nutrition Disorders; Overnutrition; Body Weight Changes; Pathological Conditions, Signs and Symptoms; Behavior; Nutritional and Metabolic Diseases; Signs and Symptoms; Overweight; Obesity; Weight Loss; Body Weight; Health Behavior
• Other Study ID Numbers: 87051

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: YES
• IPD Plan Description: The de-identified dataset and metadata will be made available through a public repository. It will include the primary outcome (weight change), secondary outcomes, and participant level characteristics. Data will be available in an Excel spreadsheet, whereby each row corresponds to a unique participant's data, and columns represent the different variables mentioned, by time point.
• IPD Sharing Time Frame: The shared dataset and metadata will be preserved and made publicly available to share for at least 3 years following completion of the project, in accordance with NIH regulations. They will be made available upon publication of the primary outcomes paper in a peer-reviewed journal, or at the end of the grant period (whichever comes first).
• IPD Sharing Access Criteria: Publicly available.
• IPD Sharing Supporting Information Type: STUDY_PROTOCOL; SAP; ICF

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No