Obesity
Conditions
Keywords
obesity, diet, reducing
Brief summary
The purpose of this study is to learn how to personalize weight loss programs. In this research we will study: 1. Whether a weight loss counselor should decide if the traditional weight loss therapy is working either after 3 or 7 weekly sessions of therapy and 2. For those who haven't lost the expected amount of weight, whether it is more effective to add packaged meals to the traditional weight loss therapy or to change to an enhanced version of behavioral weight loss therapy.
Detailed description
The US Preventive Services Task Force recommends referral to behavioral weight loss programs to help obese adults achieve a clinically meaningful weight loss of 8-10% of starting body weight. However, approximately half of participants are unable to achieve this goal. Despite this, aone size fits all approach is the norm, a major drawback because those who do not respond can in fact be detected early. This gap in weight loss intervention science calls for an adaptive intervention approach that could provide the right treatment at the right time for the right person. Adaptive interventions individualize treatment through empirically-supported decision rules advising when and how treatments should unfold over time to maximize effectiveness. Sequential Multiple Assignment Randomized Trials (SMART), developed explicitly to build the best adaptive interventions, use experimental design principles to develop these decision rules. The investigators will use a SMART to systematically evaluate therapeutic approach and timing differences for intervening with those who do not respond to a behavioral weight loss program. Self-regulation challenges have been identified as a major adherence barrier. Two attractive options to address self-regulation difficulties are: 1) supplementing behavioral treatment with Meal Replacements (MR) which decreases the need for self-regulation; and 2) switching therapeutic approaches by using an enhanced version of behavioral weight loss therapy that teaches acceptance based behavioral skills which boost capacity for self-regulation. Additionally, two time points for intervening with non-responders will be evaluated: 1) 3 weeks, based on current weight loss trial evidence; and 2) 7 weeks, based on average time used in the existing stepped care literature. Adults (n=500) will be recruited and will receive individual behavioral weight loss treatment (BWL). Participants will be randomized to either: 1) treatment response assessment at 3 weeks or 2) treatment response assessment at 7 weeks. Subjects who have lost the expected amount of weight at their assessment point, will continue with traditional behavioral weight loss therapy. For those who have not lost the expected amount of weight, we will re-randomize them to either meal replacements in addition to the traditional weight loss therapy or to the enhanced version of behavioral weight loss therapy.
Interventions
BEHAVIORALBehavioral weight loss therapy
All participants start with behavioral weight loss therapy which consists of 20 weekly meetings wtih a weight loss coach. Session components will include weekly weigh-in, discussion of progress and challenges and discussion of scheduled session topic. Dietary goals and physical activity goals are set. After their first session, participants are randomized to have their weight assessed at either their 3rd session or their 7th session. Both the participant and their coach are blinded to the randomization. If the participant has lost the expected amount of weight, they continue with behavioral weight loss therapy for the full 20 session.
BEHAVIORALPortion-controlled meals
Participants continue with behavioral weight loss therapy, but this is augmented with portion-controlled meals (PCM). Adherence to energy intake goals is facilitated by consuming pre-prepared meals specifically designed to meet caloric intake guidelines. PCMs reduce individuals' motivationally- and self-regulatory-dependent planning and decision making around eating. PCMs also serve as a teaching tool regarding the amount and type of food people should eat in order to produce weight loss.
BEHAVIORALAcceptance-based treatment
Switching the therapeutic approach to an enhanced behavioral weight loss therapy teaching acceptance-based behavioral skills theoretically addresses the root problem of many weight loss challenges and boosts long-term capacity for self-regulation. Acceptance based strategies are designed to help participants identify and internalize values and lasting commitment to behavior consistent with these values. The strategies focus on increasing people's ability to forgo more pleasurable options (e.g., hedonic pleasure of food) in favor of behavior that is distinctly less pleasurable or even aversive (remaining hungry, anxious, bored). The inability to tolerate such distress is directly associated with failure of self-regulation.
Sponsors
Drexel University
University of Michigan
University of Minnesota
University of Washington
National Cancer Institute (NCI)
HealthPartners Institute
Study design
Allocation
RANDOMIZED
Intervention model
SEQUENTIAL
Primary purpose
TREATMENT
Masking
NONE
Eligibility
Sex/Gender
ALL
Age
21 Years to 70 Years
Healthy volunteers
Yes
Inclusion criteria
* Between the ages of 21 - 70 * BMI between 30 - 45 kg/m2 * Able to walk 2 blocks without stopping * Able to attend measurement and intervention activities in the Twin Cities area in person for 18 months
Exclusion criteria
* Self-reported pregnancy or breastfeeding baby in last 6 months or planning a pregnancy in the next 18 months * History of bariatric surgery * Current or previous diagnosis of anorexia nervosa or bulimia nervosa * Food allergies, intolerances
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Weight Change | 6 months and 18 months after baseline | Weight change from baseline to 6 months and to 18 months among suboptimal responders to behavioral weight loss therapy. |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| Weight Change | 6 and 18 months after baseline | Mixed model-estimated weight change from baseline to 6 and 18 months (pooled) among all randomized participants. |
Countries
United States
Participant flow
Pre-assignment details
26 participants were lost to follow-up or quit after the initial randomization to the 3 or 7 week treatment response assessment and prior to the treatment response assessment. These participants are included in the session 3 and session 7 treatment response assessment & no-randomization groups.
Participants by arm
| Arm | Count |
|---|---|
| Week 3 Treatment Response Assessment Participants randomized to have their weight assessed at their 3rd session. If the participant has lost the expected amount of weight, they continue with standard behavioral weight loss treatment for the full 20 sessions. If they have not lost the expected amount of weight, they are re-randomized to portion controlled meals or acceptance-based treatment. | 233 |
| Week 7 Treatment Response Assessment Participants randomized to have their weight assessed at their 7th session. If the participant has lost the expected amount of weight, they continue with standard behavioral weight loss treatment for the full 20 sessions. If they have not lost the expected amount of weight, they are re-randomized to portion controlled meals or acceptance-based treatment. | 235 |
| Portion Controlled Meals Portion controlled meals: Participants assessed at the 3rd or 7th session who did not lose the expected amount of weight and were re-randomized to continue with behavioral weight loss therapy that is augmented with portion controlled meals (PCM). | 132 |
| Acceptance-based Treatment Acceptance-based treatment: Participants assessed at the 3rd or 7th session who did not lose the expected amount of weight and were re-randomized to switching the therapeutic approach to an acceptance-based treatment. | 127 |
| Total | 727 |
Baseline characteristics
| Characteristic | Week 3 Treatment Response Assessment | Total | Week 7 Treatment Response Assessment | Acceptance-based Treatment | Portion Controlled Meals |
|---|---|---|---|---|---|
| Age, Categorical Stage 1 Randomization <=18 years | 0 Participants | 0 Participants | 0 Participants | — | — |
| Age, Categorical Stage 1 Randomization >=65 years | 9 Participants | 19 Participants | 10 Participants | — | — |
| Age, Categorical Stage 1 Randomization Between 18 and 65 years | 224 Participants | 449 Participants | 225 Participants | — | — |
| Age, Categorical Stage 2 Re-Randomization <=18 years | — | 0 Participants | — | 0 Participants | 0 Participants |
| Age, Categorical Stage 2 Re-Randomization >=65 years | — | 9 Participants | — | 2 Participants | 7 Participants |
| Age, Categorical Stage 2 Re-Randomization Between 18 and 65 years | — | 250 Participants | — | 125 Participants | 125 Participants |
| Race/Ethnicity, Customized Stage 1 Randomization Hispanic, Any Race | 9 Participants | 24 Participants | 15 Participants | — | — |
| Race/Ethnicity, Customized Stage 1 Randomization Non-Hispanic Black | 34 Participants | 54 Participants | 20 Participants | — | — |
| Race/Ethnicity, Customized Stage 1 Randomization Non-Hispanic White | 177 Participants | 366 Participants | 189 Participants | — | — |
| Race/Ethnicity, Customized Stage 1 Randomization Other | 13 Participants | 24 Participants | 11 Participants | — | — |
| Race/Ethnicity, Customized Stage 2 Re-Randomization Hispanic, Any Race | — | 12 Participants | — | 8 Participants | 4 Participants |
| Race/Ethnicity, Customized Stage 2 Re-Randomization Non-Hispanic Black | — | 33 Participants | — | 15 Participants | 18 Participants |
| Race/Ethnicity, Customized Stage 2 Re-Randomization Non-Hispanic White | — | 199 Participants | — | 96 Participants | 103 Participants |
| Race/Ethnicity, Customized Stage 2 Re-Randomization Other | — | 15 Participants | — | 8 Participants | 7 Participants |
| Sex: Female, Male Stage 1 Randomization Female | 179 Participants | 357 Participants | 178 Participants | — | — |
| Sex: Female, Male Stage 1 Randomization Male | 54 Participants | 111 Participants | 57 Participants | — | — |
| Sex: Female, Male Stage 2 Re-Randomization Female | — | 222 Participants | — | 111 Participants | 111 Participants |
| Sex: Female, Male Stage 2 Re-Randomization Male | — | 37 Participants | — | 16 Participants | 21 Participants |
| Weight Stage 1 Randomization | 225.1 pounds STANDARD_DEVIATION 34.82 | 224.6 pounds STANDARD_DEVIATION 34.5 | 224.1 pounds STANDARD_DEVIATION 34.25 | — | — |
| Weight Stage 2 Re-Randomization | — | 222.4 pounds STANDARD_DEVIATION 33.91 | — | 222 pounds STANDARD_DEVIATION 33.37 | 222.8 pounds STANDARD_DEVIATION 34.55 |
Adverse events
| Event type | EG000 affected / at risk | EG001 affected / at risk | EG002 affected / at risk | EG003 affected / at risk |
|---|---|---|---|---|
| deaths Total, all-cause mortality | 0 / 233 | 0 / 235 | 0 / 132 | 0 / 127 |
| other Total, other adverse events | 0 / 233 | 0 / 235 | 0 / 132 | 0 / 127 |
| serious Total, serious adverse events | 0 / 233 | 3 / 235 | 1 / 132 | 2 / 127 |
Outcome results
Primary
Weight Change
Weight change from baseline to 6 months and to 18 months among suboptimal responders to behavioral weight loss therapy.
Time frame: 6 months and 18 months after baseline
Population: Participants included in this analysis were suboptimal responders to behavioral weight loss therapy whose initial treatment was augmented with portion-controlled meals or switched to acceptance-based treatment.
| Arm | Measure | Group | Value (MEAN) |
|---|---|---|---|
| Portion-controlled Meals | Weight Change | 18M | -8.5 pounds |
| Portion-controlled Meals | Weight Change | 6M | -18.4 pounds |
| Acceptance-based Treatment | Weight Change | 18M | -7.4 pounds |
| Acceptance-based Treatment | Weight Change | 6M | -15.7 pounds |
Comparison: H1 predicted that suboptimal responders re-randomized to PCM would lose more weight at 6m (H1a) while those re-randomized to ABT would lose more weight at 18m (H1b). A mixed linear model predicted weight change from fixed re-randomization, measurement time, the re-randomization by measurement time interaction and covariate parameters.p-value: 0.25Mixed Models Analysis
Secondary
Weight Change
Mixed model-estimated weight change from baseline to 6 and 18 months (pooled) among all randomized participants.
Time frame: 6 and 18 months after baseline
Population: Participants included in this analysis were all randomized participants, who had been randomly assigned to be assessed for treatment response 3 weeks (Early TRA) or 7 weeks (Late TRA) after initiating behavioral weight loss therapy.
| Arm | Measure | Value (MEAN) |
|---|---|---|
| Portion-controlled Meals | Weight Change | -16.6 pounds |
| Acceptance-based Treatment | Weight Change | -16.7 pounds |
Comparison: Hypothesis 2 predicted that among all participants, those randomized to Early TRA would lose more weight at 6 and 18 months than those randomized to Late TRA. A mixed linear model predicted weight change from fixed treatment response assessment timing and covariate parameters.p-value: 0.9695% CI: [-2.4, 2.3]Mixed Models Analysis