Obesity
Conditions
Keywords
Weight Loss Maintenance
Brief summary
This study aims to test two strategies for weight loss maintenance. It involves two phases, a weight loss phase and a maintenance phase. During Phase I (the weight loss phase), participants will receive a 16-week, Web-based behavioral weight loss program that involves access to weekly weight loss information and weekly personalized feedback on diet, activity, and weight loss goals. Individuals who lose at least 5% of their initial body weight during this program, will be invited to participate in Phase II. During Phase II, two 4-month treatments for weight loss maintenance will be tested. At the beginning of Phase II, participants will be randomly assigned to one of the two maintenance programs: (1) a behavioral maintenance program that involves in-person group meetings plus daily exercises in which information about a healthy lifestyle is reviewed or (2) a behavioral maintenance program that involves in-person group meetings plus daily exercises in which descriptions of positive future events are reviewed. Throughout the study, participants will complete assessments that examine the effects of the interventions on delay discounting, physical activity, weight, and other important health and psychosocial outcomes.
Interventions
BEHAVIORALWeight Loss Maintenance + Healthy Thinking
Contingent upon participants losing 5% of body weight or more in Phase I (weight loss) of this trial, participants will receive a 4-month behavioral weight maintenance intervention consisting of 7 sessions that focus on evidence-based weight management strategies focused on diet, exercise, and behavioral skills. In this treatment, participants will be asked to read short passages related to nutrition and a healthy lifestyle through our study website twice a day for the duration of treatment.
BEHAVIORALWeight Loss Maintenance Treatment + Future Thinking
Contingent upon participants losing 5% of body weight or more in Phase I (weight loss) of this trial, participants will receive a 4-month behavioral weight maintenance intervention consisting of 7 sessions that focus on evidence-based weight management strategies focused on diet, exercise, and behavioral skills. In this treatment, participants will create descriptions of upcoming positive events and will be asked to read short passages through our study website at least twice a day for the duration of treatment.
Sponsors
National Institute of Nursing Research (NINR)
University at Buffalo
Kent State University
University of Southern California
University of Connecticut
Study design
Allocation
RANDOMIZED
Intervention model
PARALLEL
Primary purpose
TREATMENT
Masking
SINGLE (Outcomes Assessor)
Eligibility
Sex/Gender
ALL
Age
18 Years to 70 Years
Healthy volunteers
No
Inclusion criteria
* Age between 18-70 * Body Mass Index between 30-50 * English Speaking * Have a smartphone that can be used for study activities
Exclusion criteria
* Report being unable to walk 2 blocks without stopping * Are currently participating in weight loss treatment, have a history of bariatric surgery, or lost ≥5% in the past 6-months * Are pregnant or plan to become pregnant within 1 year * Report a heart condition, chest pain during periods of rest or activity, or loss of consciousness on the Physical Activity Readiness Questionnaire * Report a medical condition that could jeopardize their safety in a weight control program with diet and exercise guidelines * History of or current traumatic brain injury, dementia or Alzheimer's disease; a history of Multiple Sclerosis, or other neurological disorders * Report conditions that, in the judgment of the PI, would render them unlikely to follow the protocol (e.g., relocation, dementia, unable to read and write in English) * Have no Internet access or unwilling to use personal smartphone for study.
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Weekly Moderate-Vigorous Physical Activity Minutes, Accelerometry | Phase II baseline to 1 month, 2 months and 4 months (end of treatment) | Change in weekly minutes of moderate to vigorous physical activity measured via a waist worn accelerometer during the Phase II maintenance program. At each assessment time point, participants were instructed to wear the accelerometer on their right waist during all waking hours for 7 days. Participants with a minimum of 600 min of valid daily wear time for at least 4 days were included in reported outcomes. |
| Delay Discounting (Adjusting Amount Task) | Phase II baseline to 1 month, 2 months and 4 months (end of treatment) | Change in delay discounting measured using the Adjusting Amount task during the Phase II maintenance program. Delay discounting refers to the decline in the present value of a reward with delay to its receipt. The Adjusting Amount task identifies an individual's discount rate, which reflects how much they devalue future rewards. In the task, participants are presented with a choice between a smaller, immediate (hypothetical) monetary reward and a larger, delayed (hypothetical) monetary reward. Then, using a titration procedure, the delayed reward amount is adjusted based on the participant's choices to find the point at which they are indifferent between the two options (i.e., discounting rate). The discount rate is represented by k. A higher k value means a steeper discount rate, indicating a greater preference for immediate rewards and a higher devaluation of future rewards. |
| Delay Discounting (Monetary Choice Questionnaire) | Phase II baseline to 2 months and 4 months (end of treatment) | Change in delay discounting measured using the Monetary Choice Questionnaire (MCQ) task during the Phase II maintenance program. Delay discounting refers to the decline in the present value of a reward with delay to its receipt. The MCQ identifies an individual's discount rate, which reflects how much they devalue future rewards. In the task, each question asks participants to make a choice between a smaller, immediate (hypothetical) monetary reward and a larger, delayed (hypothetical) reward. Unlike the Adjusting Amount task, each MCQ question includes different combinations of delay periods and reward amounts that are not influenced by previous responses (i.e., delay periods and reward amounts are static and the same for each participant). The discount rate is represented by k. A higher k value means a steeper discount rate, indicating a greater preference for immediate rewards and a higher devaluation of future rewards. |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| Weight | 4 months | Weight change from end of Phase 1 weight loss program to end of Phase II maintenance program |
Countries
United States
Participant flow
Pre-assignment details
Following enrollment, participants began Phase I, a 16-week weight loss program aiming to induce clinically significant weight loss (5% of starting body weight). After Phase I, eligibility to continue to Phase II (weight maintenance) was evaluated. Those who lost at least 5% of their body weight remained eligible. Given that Phase II was the primary focus of the study, primary outcome data were analyzed only from randomized, Phase II participants (eligible subset of Phase I participants).
Participants by arm
| Arm | Count |
|---|---|
| Behavioral Weight Loss Maintenance + Healthy Thinking Contingent upon participants losing 5% of body weight or more in Phase I (weight loss) of this trial, participants will receive a 4-month behavioral weight maintenance intervention consisting of 7 sessions that focus on evidence-based weight management strategies focused on diet, exercise, and behavioral skills. In this treatment, participants will be asked to read short passages related to nutrition and a healthy lifestyle through our study website twice a day for the duration of treatment.
Weight Loss Maintenance + Healthy Thinking: Contingent upon participants losing 5% of body weight or more in Phase I (weight loss) of this trial, participants will receive a 4-month behavioral weight maintenance intervention consisting of 7 sessions that focus on evidence-based weight management strategies focused on diet, exercise, and behavioral skills. In this treatment, participants will be asked to read short passages related to nutrition and a healthy lifestyle through our study website twice a day for the duration of treatment. | 24 |
| Behavioral Weight Loss Maintenance Treatment + Future Thinking Contingent upon participants losing 5% of body weight or more in Phase I (weight loss) of this trial, participants will receive a 4-month behavioral weight maintenance intervention consisting of 7 sessions that focus on evidence-based weight management strategies focused on diet, exercise, and behavioral skills. In this treatment, participants will create descriptions of upcoming positive events and will be asked to read short passages through our study website at least twice a day for the duration of treatment.
Weight Loss Maintenance Treatment + Future Thinking: Contingent upon participants losing 5% of body weight or more in Phase I (weight loss) of this trial, participants will receive a 4-month behavioral weight maintenance intervention consisting of 7 sessions that focus on evidence-based weight management strategies focused on diet, exercise, and behavioral skills. In this treatment, participants will create descriptions of upcoming positive events and will be asked to read short passages through our study website at least twice a day for the duration of treatment. | 28 |
| Phase I Only (Weight Loss Phase): 16 Weeks This group consists of the participants who enrolled in Phase I (Weight Loss Phase) but were not randomized to Phase I because they dropped out or were not eligible for Phase II (Weight Maintenance Phase). | 108 |
| Total | 160 |
Baseline characteristics
| Characteristic | Behavioral Weight Loss Maintenance + Healthy Thinking | Behavioral Weight Loss Maintenance Treatment + Future Thinking | Phase I Only (Weight Loss Phase): 16 Weeks | Total |
|---|---|---|---|---|
| Age, Continuous | 45.83 years STANDARD_DEVIATION 10.26 | 48.11 years STANDARD_DEVIATION 13.02 | 46.80 years STANDARD_DEVIATION 12.03 | 46.88 years STANDARD_DEVIATION 11.91 |
| Delay Discounting (Adjusting Amount Task) | 0.002589348 k-value STANDARD_DEVIATION 0.003302 | 0.021894643 k-value STANDARD_DEVIATION 0.108428 | — | 0.012984507 k-value STANDARD_DEVIATION 0.07952 |
| Delay Discounting (Monetary Choice Questionnaire) | 0.017834 k-value STANDARD_DEVIATION 0.019678 | 0.025506 k-value STANDARD_DEVIATION 0.047832 | — | 0.021965 k-value STANDARD_DEVIATION 0.037427 |
| Ethnicity (NIH/OMB) Hispanic or Latino | 3 Participants | 0 Participants | 14 Participants | 17 Participants |
| Ethnicity (NIH/OMB) Not Hispanic or Latino | 21 Participants | 28 Participants | 94 Participants | 143 Participants |
| Ethnicity (NIH/OMB) Unknown or Not Reported | 0 Participants | 0 Participants | 0 Participants | 0 Participants |
| Race/Ethnicity, Customized American Indian or Alaskan Native | 0 Participants | 0 Participants | 0 Participants | 0 Participants |
| Race/Ethnicity, Customized Asian | 0 Participants | 1 Participants | 3 Participants | 4 Participants |
| Race/Ethnicity, Customized Black or African American | 3 Participants | 0 Participants | 24 Participants | 27 Participants |
| Race/Ethnicity, Customized More than One Race | 2 Participants | 0 Participants | 4 Participants | 6 Participants |
| Race/Ethnicity, Customized Native Hawaiian or other Pacific Islander | 0 Participants | 0 Participants | 0 Participants | 0 Participants |
| Race/Ethnicity, Customized Other | 0 Participants | 1 Participants | 1 Participants | 2 Participants |
| Race/Ethnicity, Customized Prefer not to answer | 0 Participants | 2 Participants | 3 Participants | 5 Participants |
| Race/Ethnicity, Customized White | 19 Participants | 24 Participants | 73 Participants | 116 Participants |
| Region of Enrollment United States | 24 participants | 28 participants | 108 participants | 160 participants |
| Sex: Female, Male Female | 21 Participants | 21 Participants | 96 Participants | 138 Participants |
| Sex: Female, Male Male | 3 Participants | 7 Participants | 12 Participants | 22 Participants |
| Weekly Moderate-Vigorous Physical Activity Minutes, Accelerometry | 194.29 minutes STANDARD_DEVIATION 119.595 | 229.82 minutes STANDARD_DEVIATION 162.393 | — | 213.42 minutes STANDARD_DEVIATION 143.985 |
| Weight | 94.89 kilograms STANDARD_DEVIATION 17.09 | 92.00 kilograms STANDARD_DEVIATION 16.38 | — | 93.33 kilograms STANDARD_DEVIATION 16.61 |
Adverse events
| Event type | EG000 affected / at risk | EG001 affected / at risk | EG002 affected / at risk |
|---|---|---|---|
| deaths Total, all-cause mortality | 0 / 24 | 0 / 28 | 0 / 108 |
| other Total, other adverse events | 9 / 24 | 7 / 28 | 4 / 108 |
| serious Total, serious adverse events | 0 / 24 | 0 / 28 | 2 / 108 |
Outcome results
Primary
Delay Discounting (Adjusting Amount Task)
Change in delay discounting measured using the Adjusting Amount task during the Phase II maintenance program. Delay discounting refers to the decline in the present value of a reward with delay to its receipt. The Adjusting Amount task identifies an individual's discount rate, which reflects how much they devalue future rewards. In the task, participants are presented with a choice between a smaller, immediate (hypothetical) monetary reward and a larger, delayed (hypothetical) monetary reward. Then, using a titration procedure, the delayed reward amount is adjusted based on the participant's choices to find the point at which they are indifferent between the two options (i.e., discounting rate). The discount rate is represented by k. A higher k value means a steeper discount rate, indicating a greater preference for immediate rewards and a higher devaluation of future rewards.
Time frame: Phase II baseline to 1 month, 2 months and 4 months (end of treatment)
Population: The number of participants analyzed in each group reflects the number of randomized participants that completed the delay discounting measure at each timepoint.
| Arm | Measure | Group | Value (MEAN) | Dispersion |
|---|---|---|---|---|
| Behavioral Weight Loss Maintenance + Healthy Thinking | Delay Discounting (Adjusting Amount Task) | Baseline to 1-month | 0.001280 k-value | Standard Deviation 0.003962 |
| Behavioral Weight Loss Maintenance + Healthy Thinking | Delay Discounting (Adjusting Amount Task) | Baseline to 2-month | 0.000165 k-value | Standard Deviation 0.003824 |
| Behavioral Weight Loss Maintenance + Healthy Thinking | Delay Discounting (Adjusting Amount Task) | Baseline to 4-month | -0.000071 k-value | Standard Deviation 0.003989 |
| Behavioral Weight Loss Maintenance Treatment + Future Thinking | Delay Discounting (Adjusting Amount Task) | Baseline to 1-month | 0.107264 k-value | Standard Deviation 0.547971 |
| Behavioral Weight Loss Maintenance Treatment + Future Thinking | Delay Discounting (Adjusting Amount Task) | Baseline to 2-month | 0.108922 k-value | Standard Deviation 0.558786 |
| Behavioral Weight Loss Maintenance Treatment + Future Thinking | Delay Discounting (Adjusting Amount Task) | Baseline to 4-month | 0.101414 k-value | Standard Deviation 0.5384 |
Primary
Delay Discounting (Monetary Choice Questionnaire)
Change in delay discounting measured using the Monetary Choice Questionnaire (MCQ) task during the Phase II maintenance program. Delay discounting refers to the decline in the present value of a reward with delay to its receipt. The MCQ identifies an individual's discount rate, which reflects how much they devalue future rewards. In the task, each question asks participants to make a choice between a smaller, immediate (hypothetical) monetary reward and a larger, delayed (hypothetical) reward. Unlike the Adjusting Amount task, each MCQ question includes different combinations of delay periods and reward amounts that are not influenced by previous responses (i.e., delay periods and reward amounts are static and the same for each participant). The discount rate is represented by k. A higher k value means a steeper discount rate, indicating a greater preference for immediate rewards and a higher devaluation of future rewards.
Time frame: Phase II baseline to 2 months and 4 months (end of treatment)
Population: The number of participants analyzed at each timepoint reflects the number of randomized participants who completed this measure.
| Arm | Measure | Group | Value (MEAN) | Dispersion |
|---|---|---|---|---|
| Behavioral Weight Loss Maintenance + Healthy Thinking | Delay Discounting (Monetary Choice Questionnaire) | Baseline to 2-months | 0.002863 k-value | Standard Deviation 0.029509 |
| Behavioral Weight Loss Maintenance + Healthy Thinking | Delay Discounting (Monetary Choice Questionnaire) | Baseline to 4-months | -0.001625 k-value | Standard Deviation 0.022689 |
| Behavioral Weight Loss Maintenance Treatment + Future Thinking | Delay Discounting (Monetary Choice Questionnaire) | Baseline to 4-months | -0.004049 k-value | Standard Deviation 0.01575 |
| Behavioral Weight Loss Maintenance Treatment + Future Thinking | Delay Discounting (Monetary Choice Questionnaire) | Baseline to 2-months | -0.007161 k-value | Standard Deviation 0.01793 |
Primary
Weekly Moderate-Vigorous Physical Activity Minutes, Accelerometry
Change in weekly minutes of moderate to vigorous physical activity measured via a waist worn accelerometer during the Phase II maintenance program. At each assessment time point, participants were instructed to wear the accelerometer on their right waist during all waking hours for 7 days. Participants with a minimum of 600 min of valid daily wear time for at least 4 days were included in reported outcomes.
Time frame: Phase II baseline to 1 month, 2 months and 4 months (end of treatment)
Population: The number of participants analyzed in this outcome measure generally reflects the number that completed accelerometry assessment procedures at each timepoint. At the 2 month assessment, one Healthy Thinking participant's data was excluded due to insufficient device wear time. All other missing participant data indicates that the participant did not complete this assessment procedure.
| Arm | Measure | Group | Value (MEAN) | Dispersion |
|---|---|---|---|---|
| Behavioral Weight Loss Maintenance + Healthy Thinking | Weekly Moderate-Vigorous Physical Activity Minutes, Accelerometry | Phase II baseline to 1-month | -21.4286 Minutes | Standard Deviation 61.52851 |
| Behavioral Weight Loss Maintenance + Healthy Thinking | Weekly Moderate-Vigorous Physical Activity Minutes, Accelerometry | Phase II baseline to 2-month | 19.6000 Minutes | Standard Deviation 100.369 |
| Behavioral Weight Loss Maintenance + Healthy Thinking | Weekly Moderate-Vigorous Physical Activity Minutes, Accelerometry | Phase II baseline to 4-month | -12.7143 Minutes | Standard Deviation 96.02403 |
| Behavioral Weight Loss Maintenance Treatment + Future Thinking | Weekly Moderate-Vigorous Physical Activity Minutes, Accelerometry | Phase II baseline to 1-month | -53.9600 Minutes | Standard Deviation 149.60712 |
| Behavioral Weight Loss Maintenance Treatment + Future Thinking | Weekly Moderate-Vigorous Physical Activity Minutes, Accelerometry | Phase II baseline to 2-month | -38.6800 Minutes | Standard Deviation 108.40846 |
| Behavioral Weight Loss Maintenance Treatment + Future Thinking | Weekly Moderate-Vigorous Physical Activity Minutes, Accelerometry | Phase II baseline to 4-month | -65.7308 Minutes | Standard Deviation 126.15627 |
Secondary
Weight
Weight change from end of Phase 1 weight loss program to end of Phase II maintenance program
Time frame: 4 months
| Arm | Measure | Value (MEAN) | Dispersion |
|---|---|---|---|
| Behavioral Weight Loss Maintenance + Healthy Thinking | Weight | -11.87 kilograms | Standard Deviation 7.66 |
| Behavioral Weight Loss Maintenance Treatment + Future Thinking | Weight | -9.28 kilograms | Standard Deviation 6.63 |