Health Behavior, Obesity, Overweight, Weight Loss
Conditions
Keywords
weight loss, Multiphase Optimization Strategy, behavioral intervention, factorial trial, goal setting, time-restricted eating
Brief summary
The goal of this pilot trial is to learn about the optimal intensity level of goals in a digital weight loss intervention among adults with overweight or obesity. The main questions of the study are to assess the feasibility and acceptability of different goal intensities across four domains (calorie goal, step goal, eating window goal, red zone food goal). The investigators will recruit 32 total participants to the trial. Recruitment will occur through remote channels. Interested individuals will be directed to an online screening questionnaire; those who are eligible will then be invited to attend an initial remote session with study personnel to ensure interest and eligibility in the study. The weight loss intervention will last 10 weeks, and all participants will receive a "core" treatment consisting of self-monitoring weight, food intake, and steps (all via digital tools provided by the study team), along with behavioral lessons, action plans, and tailored feedback. Depending on which group participants are assigned to in the study, individuals will receive either a more or less challenging goal across the four domains. All study tasks will occur remotely, thus, participants will never come in-person for any tasks. Assessment of body weight and other measures will occur at the beginning of the trial ("baseline"), and at 4 weeks and 10 weeks. The investigators will use the Multiphase Optimization Strategy (MOST) framework to identify which of the goal intensity levels result in meaningful engagement and weight loss. The current study is the first step towards answering this question; it is designed as a pilot factorial trial, which focuses on feasibility and acceptability. In total, there will be 16 treatment conditions.
Interventions
BEHAVIORALCore Behavioral Weight Loss Intervention
All participants will receive a 10-week core behavioral weight loss treatment consisting of: self-monitoring weight, steps, and food intake; behavioral lessons; action plans; and tailored feedback. The intervention will be delivered remotely via email and digital tools (such as a smart scale, Fitbit activity tracker, and Fitbit app).
BEHAVIORALEasier Step Goal
Participants will receive an easier daily step goal.
BEHAVIORALHarder Step Goal
Participants will receive a more challenging daily step goal.
BEHAVIORALEasier Calorie Goal
Participants will receive an easier daily calorie goal.
BEHAVIORALHarder Calorie Goal
Participants will receive a more challenging daily calorie goal.
BEHAVIORALEasier Eating Window Goal
Participants will receive an easier daily eating window goal.
BEHAVIORALHarder Eating Window Goal
Participants will receive a more challenging daily eating window goal, akin to time-restricted eating.
BEHAVIORALEasier Red Zone Food Goal
Participants will receive an easier daily Red Zone Food goal.
BEHAVIORALHarder Red Zone Food Goal
Participants will receive a more challenging daily Red Zone Food goal.
Sponsors
Stanford University
National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK)
Study design
Allocation
RANDOMIZED
Intervention model
FACTORIAL
Primary purpose
TREATMENT
Masking
NONE
Intervention model description
This study uses a full factorial experimental design to test the impact of four intervention components, each with two levels (i.e., a 2x2x2x2).
Eligibility
Sex/Gender
ALL
Age
18 Years to No maximum
Healthy volunteers
No
Inclusion criteria
* adults (ages 18+ years) * body mass index (BMI) 25.0 to 45.0 kg/m\^2 * smartphone ownership * willingness to install the Fitbit mobile app on their phone * access to a personal email account * English language proficiency * interest in losing weight through behavioral strategies * living in the United States
Exclusion criteria
* concurrent enrollment in another weight management intervention * loss of ≥10 lbs. in the past 6 months * current use of a weight loss medication * prior or planned bariatric surgery * current or planned pregnancy in the trial period * currently breastfeeding * lives 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 (assessed by the Physical Activity Readiness Questionnaire) * if weight loss is contraindicated or might be impacted by a condition or medication (e.g., end stage renal disease, cancer, schizophrenia, dementia, steroids, anti-psychotics) * 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
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| (Feasibility) Engagement in Self-monitoring Body Weight | baseline to 10 weeks | average percentage of days in the 10-week intervention of self-monitoring weight (assessed objectively via smart scale); a benchmark of self-monitoring 75% of days would indicate feasibility |
| (Feasibility) Engagement in Self-monitoring Steps | baseline to 10 weeks | average percentage of days in the 10-week intervention of self-monitoring steps (assessed objectively via Fitbit activity tracker); a benchmark of self-monitoring 75% of days would indicate feasibility |
| (Feasibility) Engagement in Self-monitoring Dietary Intake | baseline to 10 weeks | average percentage of days in the 10-week intervention of self-monitoring dietary intake (assessed via Fitbit mobile app); a benchmark of self-monitoring 75% of days would indicate feasibility |
| (Acceptability) Would You Recommend the Weight Loss Program to a Friend Who is Trying to Lose Weight? | 10 weeks | 1-item measure; a benchmark of 80% of participants answering "yes" would indicate acceptability |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| (Feasibility) Retention Rate | 10 weeks | the proportion of participants who submitted a weight entry at 10 weeks; a benchmark of 80% would indicate feasibility |
| (Feasibility) Survey Completion Rate | baseline; 10 weeks | the proportion of participants who completed the web survey; a benchmark of 80% would indicate feasibility |
| (Feasibility) Goal Attainment of Calorie Goal | baseline to 10 weeks | average percentage of days in the 10-week intervention of meeting the daily calorie goal (assessed via Fitbit mobile app); a benchmark of 75% of days would indicate feasibility |
| (Feasibility) Goal Attainment of Step Goal | baseline to 10 weeks | average percentage of days in the 10-week intervention of meeting the daily step goal (assessed via Fitbit activity tracker); a benchmark of 75% of days would indicate feasibility |
| (Feasibility) Goal Attainment of Eating Window Goal | baseline to 10 weeks | average percentage of days in the 10-week intervention of meeting the daily eating window goal (assessed via survey); a benchmark of 75% of days would indicate feasibility |
| (Feasibility) Goal Attainment of Red Zone Food Goal | baseline to 10 weeks | average percentage of days (out of days instructed to track Red Zone Foods) in the 10-week intervention of meeting the daily Red Zone Food goal (assessed via survey); a benchmark of 75% of weeks would indicate feasibility |
| Weight | baseline to 10 weeks | percentage change in weight from baseline to 10 weeks (end of intervention); assessed objectively via smart scale |
Countries
United States
Participant flow
Recruitment details
Participants were enrolled into the Ignite study during a 7-week period between December 5, 2023 and January 23, 2024. The trial was fully remote, with recruitment of adults across the United States.
Pre-assignment details
After informed consent was provided, participants were asked to complete a baseline survey, sync their e-scale and activity tracker with the Fitbit app, and submit their baseline weight. Once those tasks were completed, participants were randomized into 1 of 16 conditions.
Participants by arm
| Arm | Count |
|---|---|
| Condition 1 Calorie Goal (easier) + Step Goal (easier) + Eating Window Goal (easier) + Red Zone Food Goal (easier) | 2 |
| Condition 2 Calorie Goal (easier) + Step Goal (easier) + Eating Window Goal (easier) + Red Zone Food Goal (harder) | 2 |
| Condition 3 Calorie Goal (easier) + Step Goal (easier) + Eating Window Goal (harder) + Red Zone Food Goal (easier) | 2 |
| Condition 4 Calorie Goal (easier) + Step Goal (easier) + Eating Window Goal (harder) + Red Zone Food Goal (harder) | 2 |
| Condition 5 Calorie Goal (easier) + Step Goal (harder) + Eating Window Goal (easier) + Red Zone Food Goal (easier) | 2 |
| Condition 6 Calorie Goal (easier) + Step Goal (harder) + Eating Window Goal (easier) + Red Zone Food Goal (harder) | 2 |
| Condition 7 Calorie Goal (easier) + Step Goal (harder) + Eating Window Goal (harder) + Red Zone Food Goal (easier) | 2 |
| Condition 8 Calorie Goal (easier) + Step Goal (harder) + Eating Window Goal (harder) + Red Zone Food Goal (harder) | 2 |
| Condition 9 Calorie Goal (harder) + Step Goal (easier) + Eating Window Goal (easier) + Red Zone Food Goal (easier) | 2 |
| Condition 10 Calorie Goal (harder) + Step Goal (easier) + Eating Window Goal (easier) + Red Zone Food Goal (harder) | 2 |
| Condition 11 Calorie Goal (harder) + Step Goal (easier) + Eating Window Goal (harder) + Red Zone Food Goal (easier) | 2 |
| Condition 12 Calorie Goal (harder) + Step Goal (easier) + Eating Window Goal (harder) + Red Zone Food Goal (harder) | 2 |
| Condition 13 Calorie Goal (harder) + Step Goal (harder) + Eating Window Goal (easier) + Red Zone Food Goal (easier) | 2 |
| Condition 14 Calorie Goal (harder) + Step Goal (harder) + Eating Window Goal (easier) + Red Zone Food Goal (harder) | 2 |
| Condition 15 Calorie Goal (harder) + Step Goal (harder) + Eating Window Goal (harder) + Red Zone Food Goal (easier) | 2 |
| Condition 16 Calorie Goal (harder) + Step Goal (harder) + Eating Window Goal (harder) + Red Zone Food Goal (harder) | 2 |
| Total | 32 |
Baseline characteristics
| Characteristic | Total | Condition 16 | Condition 15 | Condition 14 | Condition 13 | Condition 12 | Condition 11 | Condition 10 | Condition 9 | Condition 1 | Condition 8 | Condition 7 | Condition 6 | Condition 5 | Condition 4 | Condition 3 | Condition 2 |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Age, Continuous | 47.7 years STANDARD_DEVIATION 13.3 | 42.5 years STANDARD_DEVIATION 2.1 | 51.5 years STANDARD_DEVIATION 0.7 | 41.5 years STANDARD_DEVIATION 17.7 | 46.5 years STANDARD_DEVIATION 27.6 | 52.0 years STANDARD_DEVIATION 11.3 | 53.5 years STANDARD_DEVIATION 14.8 | 54.0 years STANDARD_DEVIATION 18.4 | 44.0 years STANDARD_DEVIATION 11.3 | 42.5 years STANDARD_DEVIATION 9.2 | 48.5 years STANDARD_DEVIATION 0.7 | 52.0 years STANDARD_DEVIATION 18.4 | 69.5 years STANDARD_DEVIATION 0.7 | 54.0 years STANDARD_DEVIATION 17 | 33.5 years STANDARD_DEVIATION 6.4 | 30.5 years STANDARD_DEVIATION 0.7 | 47.0 years STANDARD_DEVIATION 18.4 |
| Ethnicity (NIH/OMB) Hispanic or Latino | 5 Participants | 0 Participants | 1 Participants | 1 Participants | 0 Participants | 0 Participants | 0 Participants | 0 Participants | 0 Participants | 0 Participants | 0 Participants | 1 Participants | 0 Participants | 0 Participants | 1 Participants | 1 Participants | 0 Participants |
| Ethnicity (NIH/OMB) Not Hispanic or Latino | 27 Participants | 2 Participants | 1 Participants | 1 Participants | 2 Participants | 2 Participants | 2 Participants | 2 Participants | 2 Participants | 2 Participants | 2 Participants | 1 Participants | 2 Participants | 2 Participants | 1 Participants | 1 Participants | 2 Participants |
| Ethnicity (NIH/OMB) Unknown or Not Reported | 0 Participants | 0 Participants | 0 Participants | 0 Participants | 0 Participants | 0 Participants | 0 Participants | 0 Participants | 0 Participants | 0 Participants | 0 Participants | 0 Participants | 0 Participants | 0 Participants | 0 Participants | 0 Participants | 0 Participants |
| Race (NIH/OMB) American Indian or Alaska Native | 0 Participants | 0 Participants | 0 Participants | 0 Participants | 0 Participants | 0 Participants | 0 Participants | 0 Participants | 0 Participants | 0 Participants | 0 Participants | 0 Participants | 0 Participants | 0 Participants | 0 Participants | 0 Participants | 0 Participants |
| Race (NIH/OMB) Asian | 3 Participants | 0 Participants | 0 Participants | 0 Participants | 1 Participants | 0 Participants | 0 Participants | 0 Participants | 0 Participants | 1 Participants | 0 Participants | 0 Participants | 0 Participants | 0 Participants | 0 Participants | 1 Participants | 0 Participants |
| Race (NIH/OMB) Black or African American | 5 Participants | 0 Participants | 0 Participants | 0 Participants | 0 Participants | 1 Participants | 0 Participants | 0 Participants | 2 Participants | 0 Participants | 1 Participants | 0 Participants | 0 Participants | 0 Participants | 0 Participants | 0 Participants | 1 Participants |
| Race (NIH/OMB) More than one race | 3 Participants | 0 Participants | 1 Participants | 0 Participants | 0 Participants | 0 Participants | 0 Participants | 0 Participants | 0 Participants | 1 Participants | 0 Participants | 0 Participants | 0 Participants | 1 Participants | 0 Participants | 0 Participants | 0 Participants |
| Race (NIH/OMB) Native Hawaiian or Other Pacific Islander | 0 Participants | 0 Participants | 0 Participants | 0 Participants | 0 Participants | 0 Participants | 0 Participants | 0 Participants | 0 Participants | 0 Participants | 0 Participants | 0 Participants | 0 Participants | 0 Participants | 0 Participants | 0 Participants | 0 Participants |
| Race (NIH/OMB) Unknown or Not Reported | 0 Participants | 0 Participants | 0 Participants | 0 Participants | 0 Participants | 0 Participants | 0 Participants | 0 Participants | 0 Participants | 0 Participants | 0 Participants | 0 Participants | 0 Participants | 0 Participants | 0 Participants | 0 Participants | 0 Participants |
| Race (NIH/OMB) White | 21 Participants | 2 Participants | 1 Participants | 2 Participants | 1 Participants | 1 Participants | 2 Participants | 2 Participants | 0 Participants | 0 Participants | 1 Participants | 2 Participants | 2 Participants | 1 Participants | 2 Participants | 1 Participants | 1 Participants |
| Sex: Female, Male Female | 24 Participants | 0 Participants | 2 Participants | 2 Participants | 1 Participants | 2 Participants | 1 Participants | 2 Participants | 2 Participants | 2 Participants | 1 Participants | 2 Participants | 1 Participants | 2 Participants | 2 Participants | 1 Participants | 1 Participants |
| Sex: Female, Male Male | 8 Participants | 2 Participants | 0 Participants | 0 Participants | 1 Participants | 0 Participants | 1 Participants | 0 Participants | 0 Participants | 0 Participants | 1 Participants | 0 Participants | 1 Participants | 0 Participants | 0 Participants | 1 Participants | 1 Participants |
| Weight | 188.9 lbs. STANDARD_DEVIATION 26.2 | 232.5 lbs. STANDARD_DEVIATION 35.4 | 201.7 lbs. STANDARD_DEVIATION 22.6 | 169.6 lbs. STANDARD_DEVIATION 0.6 | 180.2 lbs. STANDARD_DEVIATION 29.1 | 192.2 lbs. STANDARD_DEVIATION 25.2 | 193.0 lbs. STANDARD_DEVIATION 31.2 | 216.1 lbs. STANDARD_DEVIATION 5.2 | 162.4 lbs. STANDARD_DEVIATION 0.6 | 167.5 lbs. STANDARD_DEVIATION 4.6 | 178.8 lbs. STANDARD_DEVIATION 28 | 171.9 lbs. STANDARD_DEVIATION 17.7 | 204.1 lbs. STANDARD_DEVIATION 59.5 | 187.0 lbs. STANDARD_DEVIATION 16.4 | 199.2 lbs. STANDARD_DEVIATION 32 | 182.3 lbs. STANDARD_DEVIATION 4.2 | 184.7 lbs. STANDARD_DEVIATION 22.6 |
Adverse events
| Event type | EG000 affected / at risk | EG001 affected / at risk | EG002 affected / at risk | EG003 affected / at risk | EG004 affected / at risk | EG005 affected / at risk | EG006 affected / at risk | EG007 affected / at risk | EG008 affected / at risk | EG009 affected / at risk | EG010 affected / at risk | EG011 affected / at risk | EG012 affected / at risk | EG013 affected / at risk | EG014 affected / at risk | EG015 affected / at risk |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| deaths Total, all-cause mortality | 0 / 2 | 0 / 2 | 0 / 2 | 0 / 2 | 0 / 2 | 0 / 2 | 0 / 2 | 0 / 2 | 0 / 2 | 0 / 2 | 0 / 2 | 0 / 2 | 0 / 2 | 0 / 2 | 0 / 2 | 0 / 2 |
| other Total, other adverse events | 0 / 2 | 0 / 2 | 0 / 2 | 0 / 2 | 0 / 2 | 0 / 2 | 0 / 2 | 0 / 2 | 0 / 2 | 0 / 2 | 0 / 2 | 0 / 2 | 0 / 2 | 0 / 2 | 0 / 2 | 0 / 2 |
| serious Total, serious adverse events | 0 / 2 | 0 / 2 | 0 / 2 | 0 / 2 | 0 / 2 | 0 / 2 | 0 / 2 | 0 / 2 | 0 / 2 | 0 / 2 | 0 / 2 | 0 / 2 | 0 / 2 | 0 / 2 | 0 / 2 | 0 / 2 |
Outcome results
Primary
(Acceptability) Would You Recommend the Weight Loss Program to a Friend Who is Trying to Lose Weight?
1-item measure; a benchmark of 80% of participants answering yes would indicate acceptability
Time frame: 10 weeks
Population: Among completers of 10-week survey
| Arm | Measure | Value (COUNT_OF_PARTICIPANTS) |
|---|---|---|
| All Participants | (Acceptability) Would You Recommend the Weight Loss Program to a Friend Who is Trying to Lose Weight? | 29 Participants |
Primary
(Feasibility) Engagement in Self-monitoring Body Weight
average percentage of days in the 10-week intervention of self-monitoring weight (assessed objectively via smart scale); a benchmark of self-monitoring 75% of days would indicate feasibility
Time frame: baseline to 10 weeks
| Arm | Measure | Value (MEDIAN) |
|---|---|---|
| All Participants | (Feasibility) Engagement in Self-monitoring Body Weight | 89 % of intervention days |
Primary
(Feasibility) Engagement in Self-monitoring Dietary Intake
average percentage of days in the 10-week intervention of self-monitoring dietary intake (assessed via Fitbit mobile app); a benchmark of self-monitoring 75% of days would indicate feasibility
Time frame: baseline to 10 weeks
| Arm | Measure | Value (MEDIAN) |
|---|---|---|
| All Participants | (Feasibility) Engagement in Self-monitoring Dietary Intake | 54 % of intervention days |
| Step Goal: Harder | (Feasibility) Engagement in Self-monitoring Dietary Intake | 79 % of intervention days |
Primary
(Feasibility) Engagement in Self-monitoring Steps
average percentage of days in the 10-week intervention of self-monitoring steps (assessed objectively via Fitbit activity tracker); a benchmark of self-monitoring 75% of days would indicate feasibility
Time frame: baseline to 10 weeks
| Arm | Measure | Value (MEDIAN) |
|---|---|---|
| All Participants | (Feasibility) Engagement in Self-monitoring Steps | 100 % of intervention days |
| Step Goal: Harder | (Feasibility) Engagement in Self-monitoring Steps | 100 % of intervention days |
Secondary
(Feasibility) Goal Attainment of Calorie Goal
average percentage of days in the 10-week intervention of meeting the daily calorie goal (assessed via Fitbit mobile app); a benchmark of 75% of days would indicate feasibility
Time frame: baseline to 10 weeks
Population: among participants with ≥1 day of self-monitoring calories
| Arm | Measure | Value (MEDIAN) |
|---|---|---|
| All Participants | (Feasibility) Goal Attainment of Calorie Goal | 43 % of intervention days |
| Step Goal: Harder | (Feasibility) Goal Attainment of Calorie Goal | 29 % of intervention days |
Secondary
(Feasibility) Goal Attainment of Eating Window Goal
average percentage of days in the 10-week intervention of meeting the daily eating window goal (assessed via survey); a benchmark of 75% of days would indicate feasibility
Time frame: baseline to 10 weeks
Population: among participants with ≥ 1 day of self-monitoring eating window
| Arm | Measure | Value (MEDIAN) |
|---|---|---|
| All Participants | (Feasibility) Goal Attainment of Eating Window Goal | 67 % of intervention days |
| Step Goal: Harder | (Feasibility) Goal Attainment of Eating Window Goal | 81 % of intervention days |
Secondary
(Feasibility) Goal Attainment of Red Zone Food Goal
average percentage of days (out of days instructed to track Red Zone Foods) in the 10-week intervention of meeting the daily Red Zone Food goal (assessed via survey); a benchmark of 75% of weeks would indicate feasibility
Time frame: baseline to 10 weeks
Population: among participants with ≥1 day of self-monitoring Red Zone Foods
| Arm | Measure | Value (MEDIAN) |
|---|---|---|
| All Participants | (Feasibility) Goal Attainment of Red Zone Food Goal | 46 % of intervention days |
| Step Goal: Harder | (Feasibility) Goal Attainment of Red Zone Food Goal | 54 % of intervention days |
Secondary
(Feasibility) Goal Attainment of Step Goal
average percentage of days in the 10-week intervention of meeting the daily step goal (assessed via Fitbit activity tracker); a benchmark of 75% of days would indicate feasibility
Time frame: baseline to 10 weeks
Population: among participants with ≥1 day of self-monitoring steps
| Arm | Measure | Value (MEDIAN) |
|---|---|---|
| All Participants | (Feasibility) Goal Attainment of Step Goal | 34 % of intervention days |
| Step Goal: Harder | (Feasibility) Goal Attainment of Step Goal | 32 % of intervention days |
Secondary
(Feasibility) Retention Rate
the proportion of participants who submitted a weight entry at 10 weeks; a benchmark of 80% would indicate feasibility
Time frame: 10 weeks
| Arm | Measure | Value (COUNT_OF_PARTICIPANTS) |
|---|---|---|
| All Participants | (Feasibility) Retention Rate | 14 Participants |
| Step Goal: Harder | (Feasibility) Retention Rate | 16 Participants |
| Step Goal: Easier | (Feasibility) Retention Rate | 15 Participants |
| Step Goal: Harder | (Feasibility) Retention Rate | 15 Participants |
| Eating Window Goal: Easier | (Feasibility) Retention Rate | 15 Participants |
| Eating Window Goal: Harder | (Feasibility) Retention Rate | 15 Participants |
| Red Zone Food Goal: Easier | (Feasibility) Retention Rate | 15 Participants |
| Red Zone Food Goal: Harder | (Feasibility) Retention Rate | 15 Participants |
Secondary
(Feasibility) Survey Completion Rate
the proportion of participants who completed the web survey; a benchmark of 80% would indicate feasibility
Time frame: baseline; 10 weeks
| Arm | Measure | Value (COUNT_OF_PARTICIPANTS) |
|---|---|---|
| All Participants | (Feasibility) Survey Completion Rate | 30 Participants |
Secondary
Weight
percentage change in weight from baseline to 10 weeks (end of intervention); assessed objectively via smart scale
Time frame: baseline to 10 weeks
| Arm | Measure | Value (MEAN) | Dispersion |
|---|---|---|---|
| All Participants | Weight | -2.72 % weight change | Standard Deviation 3.63 |
| Step Goal: Harder | Weight | -4.86 % weight change | Standard Deviation 3.3 |
| Step Goal: Easier | Weight | -3.45 % weight change | Standard Deviation 3.81 |
| Step Goal: Harder | Weight | -4.13 % weight change | Standard Deviation 3.42 |
| Eating Window Goal: Easier | Weight | -4.19 % weight change | Standard Deviation 2.79 |
| Eating Window Goal: Harder | Weight | -3.39 % weight change | Standard Deviation 4.28 |
| Red Zone Food Goal: Easier | Weight | -3.98 % weight change | Standard Deviation 2.94 |
| Red Zone Food Goal: Harder | Weight | -3.60 % weight change | Standard Deviation 4.21 |