Key Points
Question
What is the efficacy at 3 and 12 months of a widely available commercial weight management program compared with a do-it-yourself approach?
Findings
In this 3-country randomized clinical trial that included 373 adults, reductions in weight were significantly greater at both 3 and 12 months for participants in the commercial weight management program, which included reduced requirements for dietary self-monitoring, than for participants using the do-it-yourself approach.
Meaning
This randomized clinical trial found that a commercial weight management program with reduced dietary self-monitoring produced clinically significant weight loss and may partially address the need for evidence-based approaches beyond the clinic setting.
Abstract
Importance
Given the prevalence of obesity, accessible and effective treatment options are needed to manage obesity and its comorbid conditions. Commercial weight management programs are a potential solution to the lack of available treatment, providing greater access at lower cost than clinic-based approaches, but few commercial programs have been rigorously evaluated.
Objective
To compare the differences in weight change between individuals randomly assigned to a commercial weight management program and those randomly assigned to a do-it-yourself (DIY) approach.
Design, Setting, and Participants
This 1-year, randomized clinical trial conducted in the United States, Canada, and United Kingdom between June 19, 2018, and November 30, 2019, enrolled 373 adults aged 18 to 75 years with a body mass index (BMI; calculated as weight in kilograms divided by height in meters squared) of 25 to 45. Assessors were blinded to treatment conditions.
Interventions
A widely available commercial weight management program that included reduced requirements for dietary self-monitoring and recommendations for a variety of DIY approaches to weight loss.
Main Outcomes and Measures
The primary outcomes were the difference in weight change between the 2 groups at 3 and 12 months. The a priori hypothesis was that the commercial program would result in greater weight loss than the DIY approach at 3 and 12 months. Analyses were performed on an intention-to-treat basis.
Results
The study include 373 participants (272 women [72.9%]; mean [SD] BMI, 33.8 [5.2]; 77 [20.6%] aged 18-34 years, 74 [19.8%] aged 35-43 years, 82 [22.0%] aged 44-52 years, and 140 [37.5%] aged 53-75 years). At 12 months, retention rates were 88.8% (166 of 187) for the commercial weight management program group and 95.7% (178 of 186) for the DIY group. At 3 months, participants in the commercial program had a mean (SD) weight loss of −3.8 (4.1) kg vs −1.8 (3.7) kg among those in the DIY group. At 12 months, participants in the commercial program had a mean (SD) weight loss of −4.4 (7.3) kg vs −1.7 (7.3) kg among those in the DIY group. The mean difference between groups was −2.0 kg (97.5% CI, −2.9 to −1.1 kg) at 3 months (P < .001) and −2.6 kg (97.5% CI, −4.3 to −0.8 kg) at 12 months (P < .001). A greater percentage of participants in the commercial program group than participants in the DIY group achieved loss of 5% of body weight at both 3 months (40.7% [72 of 177] vs 18.6% [34 of 183]) and 12 months (42.8% [71 of 166] vs 24.7% [44 of 178]).
Conclusions and Relevance
Adults randomly assigned to a commercial weight management program with reduced requirements for dietary self-monitoring lost more weight and were more likely to achieve weight loss of 5% at 3 and 12 months than adults following a DIY approach. This study contributes data on the efficacy of commercial weight management programs and DIY weight management approaches.
Trial Registration
ClinicalTrials.gov Identifier: NCT03571893
This randomized clinical trial compares differences in weight change between individuals randomly assigned to a commercial weight management program with reduced requirements for dietary self-monitoring and individuals randomly assigned to follow a do-it-yourself approach.
Introduction
Given the widespread prevalence of obesity, accessible and effective treatment options are needed to manage obesity and its multiple comorbid conditions.1 The US Preventive Services Task Force (USPSTF) guidelines recommend that, for patients with obesity, physicians should provide intensive behavioral treatment or refer for such treatment.2 Similarly, guidelines from professional societies underscore the need for behavioral treatment as the basis for any obesity therapy.3,4 Clinic-based treatments in tertiary care centers are the most studied,5 but they have limited reach given their availability and constraints of time, training, and reimbursement for physicians and other health care professionals.
Commercial weight management programs are a potential solution to the lack of available treatment, given their greater accessibility and lower cost than clinic-based approaches.6 Although there are numerous commercial weight management programs, to our knowledge, few have been rigorously evaluated, making it difficult for practitioners to refer patients to evidence-based programs. For example, Gudzune et al7 found that among 141 commercial programs, 32 had both behavioral and nutritional components (with or without physical activity), 11 had data from randomized clinical trials of 12 weeks or more, and only 6 met USPSTF criteria.
One internationally available weight management program (WW, formerly Weight Watchers) that meets USPSTF criteria and has clear evidence to support its efficacy in safely achieving sustained, modest weight losses7,8,9 also has the most randomized clinical trials evaluating its efficacy7 and the most cost-effective nonsurgical treatment for obesity.10,11 Despite a body of published research, most studies of this commercial program were conducted in a single country,12,13,14,15 used usual care or active treatments as controls,13,14,16 and were conducted more than 10 years ago.12,14,15,16 Single-country studies limit generalization, and although active treatments are reasonable controls, many people trying to lose weight do it on their own without joining formal programs (a do-it-yourself [DIY] approach).17 Moreover, because the components and methods of commercial weight management programs change over time, it is important to continue to evaluate new iterations. A major shift in the approach of the commercial weight management program in this study has been the inclusion of hundreds of foods that do not need to be self-monitored. Partial recording of food intake was designed to reduce the well-documented burden of self-monitoring18,19,20 and is consistent with expert recommendations to modify the self-monitoring paradigm for behavioral weight management.21 Dietary self-monitoring is strongly associated with weight loss outcomes, and monitoring in greater detail may lead to greater success.22,23,24 A single-group 6-month pilot trial demonstrated the feasibility of reduced monitoring for weight loss25; however, a randomized clinical trial is needed to evaluate the effects of reducing monitoring requirements on weight loss.
The purpose of this 3-country randomized clinical trial was to compare the differences in weight change between individuals randomly assigned to a commercial weight management program with reduced requirements for dietary self-monitoring and individuals randomly assigned to follow a DIY approach. We hypothesized that the commercial program would result in greater weight loss compared with the DIY approach at 3- and 12-month follow-up.
Methods
Study Design
This study was a randomized, parallel-group, 1-year clinical trial conducted from June 19, 2018, to November 30, 2019, at the University of North Carolina (UNC) at Chapel Hill in the US; the University of British Columbia in Kelowna, British Columiba, Canada; and the University of Leeds in Leeds, West Yorkshire, England, in the United Kingdom. The primary outcome was weight change at 3 and 12 months. The study was approved by the University of North Carolina at Chapel Hill Biomedical Institutional Review Board, the North West–Preston Research Ethics Committee, and The University of British Columbia Okanagan Research Services Behavioural Research Ethics Board. Written informed consent was provided by participants. The trial protocol is included in Supplement 1.
Recruitment and Screening
Participants were recruited using methods that had previously been successful in trials within each country, with special efforts to increase recruitment of underrepresented groups. Interested individuals were directed to a universal recruitment website that included study details with links to site-specific web screeners. Research staff contacted web-eligible participants to confirm eligibility and to schedule baseline in-person consent and screening. Final eligibility was determined after the in-person visit. This report follows the Consolidated Standards of Reporting Trials (CONSORT) reporting guideline for randomized studies (Figure 1).
Figure 1. Participant Flow Diagram.
DIY indicates do-it-yourself.
Participant Eligibility
Major inclusion criteria were being 18 to 75 years of age, body mass index (BMI) of 25 to 45 (calculated as weight in kilograms divided by height in meters squared), access to a smartphone, and residence within 48.3 km of a location of this commercial weight management program. Major exclusion criteria were recent, current, or planned pregnancy; recent weight loss of 5 kg or more; health conditions or medications known to affect weight or make weight loss or unsupervised exercise unsafe; and prior or planned bariatric surgery. Full inclusion and exclusion criteria are detailed in the eMethods in Supplement 2.
Randomization and Blinding
The Data and Analysis Coordinating Unit at UNC provided randomization assignments, using a random numbers generator, with a 1:1 allocation to either the commercial program or the DIY method, stratified by clinical site, race and ethnicity status, and sex (Figure 1). After randomization, study staff who needed to be unblinded owing to study oversight requirements were not involved in follow-up assessments.
Interventions
DIY Group
Participants underwent a 15- to 30-minute meeting reviewing common DIY strategies for weight loss that are available in the public domain. Participants engaged in a short discussion of prior weight loss attempts and successes and were provided with a brief resource guide with information about a variety of strategies (diet tracking or self-monitoring apps, meal plans, meal replacements, and physical activity) and dietary approaches to reduce energy intake healthfully (low fat, low carbohydrate, vegan, and Mediterranean diet). Emphasis was placed on strategies that used dietary self-monitoring to achieve a weight loss energy deficit, and referral to free digital dietary self-monitoring resources was given. Participants were informed that 50% of people in the National Weight Control Registry, a research-based registry of individuals who had lost weight and kept it off successfully, followed a DIY approach.26 Participants were encouraged to select a DIY strategy that best fit with their preferences, adopt that strategy for at least 8 weeks, then reevaluate, and, if needed, try another strategy. Participants in the DIY group were provided a free voucher for 12 months of the commercial program at the completion of 12-month assessment. Information on the DIY approaches suggested is available in eTable 3 in Supplement 2.
Commercial Program
Similar to the the DIY group, the commercial program group had a 15- to 30-minute session directly after randomization and were provided with a code to enroll in the program at no charge for 12 months. They were guided to download the commercial program’s smartphone app and were given a list of locations of the commercial program in their community. To enable the actual enrollment in the commercial program, study staff were not involved in the delivery of the commercial program intervention, nor were any commercial program staff or locations alerted to study enrollment.
Treatment Format
Participants were encouraged to attend weekly commercial weight management program workshops (30 to 45 minutes in person) in the community. Workshops included a private weight assessment, celebrating successes and problem-solving challenges, and a discussion and handout of featured topics and skills related to weight loss and behavior change. Participants also had access to the commercial program’s app, which included self-monitoring of intake, activity, and weight; informational articles; support from coaches through 1-on-1 online chats available 24 hours a day; and an online social media peer community limited to members of the commercial program.
Dietary Approach
The commercial program assigns each food and beverage a points value per portion, based on calories, sugar, saturated fat, and protein. A unique new feature of this program was that more than 200 foods were assigned a points value of 0 and did not have to be weighed, measured, or tracked (eg, plant-based proteins, skinless chicken and turkey breast, eggs, nonfat yogurt, seafood, fruits, and most vegetables). These foods were chosen as the cornerstone of a healthy pattern based on dietary guidelines (the US Department of Agriculture and the World Health Organization) and were qualitatively assessed as having low risk of overconsumption. Participants were encouraged to track only foods that had point values greater than 0 to decrease the burden of tracking everything that was consumed. Based on the Mifflin St-Jeor formula27 to estimate resting energy expenditure, participants were given an adjusted personalized daily points budget—to account for foods consumed but not monitored—to result in a 750-kcal/d (3138-kJ/d) energy deficit.
Other Components
Participants received a personalized weekly activity goal based on their current level of activity and were encouraged to track their activity. The program also promoted the adoption of skills and techniques to shift participants’ thinking. Mindset topics were based on cognitive behavioral, acceptance-based, and positive psychology. Examples included gratitude, self-compassion, dealing with setbacks, unhelpful thinking styles, and responding to weight stigma.
Data Collection
Research staff at the clinical sites were centrally trained and certified on the study protocol and conducted measurements at baseline, 3 months, and 12 months. Participants were instructed to refrain from revealing their treatment assignment at assessment visits to try to retain blinding of staff. Assessments were conducted at the research staff offices, except in the UK, where they occurred in general practitioner practices. Data across countries were collected using a centralized REDCap28 system with deidentified data stored centrally at UNC. All participants were provided the equivalent of $175 US dollars total compensation for completing the 3 study assessments.
Primary Outcome
This trial had 2 a priori outcomes: the difference in weight loss in kilograms between groups at 3 and 12 months. Measurement protocols for body weight and height followed the National Health and Nutrition Examination survey anthropometry procedures.29
Prespecified Secondary Outcome Measures
Secondary outcomes included BMI, percentage weight change, percentage of participants achieving loss of 5% of body weight, waist circumference, blood pressure, heart rate, and flexibility as measured by the Sit and Reach Test.30 Aerobic stamina was measured using the 1-minute Sit to Stand Test across all sites and the 6-minute walk test31 in the US and Canada (not possible in the UK owing to space limitations in general practitioner practices). Other secondary outcomes were happiness, assessed with the Oxford Happiness Questionnaire32; sleep quality, assessed using the Pittsburgh Sleep Quality Index33,34; and quality of life, assessed using the Impact of Weight on Quality of Life–Lite.35 Engagement was assessed by the number of commercial program workshops attended and the number of days of commercial program app logins. In the DIY group, the methods used for weight loss were obtained via self-report.
Sample Size
Given 2 primary outcomes, α was set at .02 (Bonferonni correction). Using a 2-sided power analysis with 80% power and assuming a within-group SD of 5.0 kg, we found that a sample size of 360 individuals was sufficient to detect an effect size of 0.35 or more for weight loss (between-group difference of −1.75 kg) at 12 months, with 30% attrition. The study was planned with equal recruitment goals in each country and powered for the overall pooled effect.
Statistical Analysis
For the primary outcomes, general linear regression models were used to compare the differences in weight change (in kilograms) between the 2 groups at 3 and 12 months. These models were adjusted for country (US, Canada, or UK), race and ethnicity (White or underrepresented race and ethnicity [self-reported in the UK and categorized as racial and ethnic minority group in the US and Canada if reported as anything other than White and not Hispanic or Latino]), and sex (male or female) and included a random effect for the commercial program workshop locations to control for potential clustering. Missing weight data were imputed using a multiple (n = 100) imputation model that included site, age, race and ethnicity status, sex, educational level, height, and all available information on body weight, waist circumference, and BMI. Age was categorized into 6 groups, and educational level was categorized into 5 categories (Table 1).
Table 1. Baseline Measures by Treatment Group.
| Measure | All participants (N = 373) | DIY (n = 186) | Commercial weight management program (n = 187) |
|---|---|---|---|
| Age, No. (%), y | |||
| 18-34 | 77 (20.6) | 36 (19.4) | 41 (21.9) |
| 35-43 | 74 (19.8) | 33 (17.7) | 41 (21.9) |
| 44-52 | 82 (22.0) | 42 (22.6) | 40 (21.4) |
| 53-75 | 140 (37.5) | 75 (40.3) | 65 (34.8) |
| Race and ethnicity, No. (%) | |||
| White | 267 (71.6) | 132 (71.0) | 135 (72.2) |
| Racial and ethnic minority groupa | 106 (28.4) | 54 (29.0) | 52 (27.8) |
| Sex, No. (%) | |||
| Female | 272 (72.9) | 136 (73.1) | 136 (72.7) |
| Male | 101 (27.1) | 50 (26.9) | 51 (27.3) |
| Educational level, No. (%)b | |||
| <High school graduate | 6 (1.6) | 1 (0.5) | 5/186 (2.7) |
| High school graduate, GED, or GCSE | 51 (13.7) | 25 (13.4) | 26 (13.9) |
| Vocational school or some college or A levels | 105 (28.2) | 56 (30.1) | 49 (26.2) |
| Undergraduate degree | 129 (34.6) | 58 (31.2) | 71 (38.0) |
| Graduate degree | 81 (21.8) | 46 (24.7) | 35 (18.7) |
| BMI status, No. (%) | |||
| Overweight | 98 (26.3) | 48 (25.8) | 50 (26.7) |
| Obese | 275 (73.7) | 138 (74.2) | 137 (73.3) |
| Weight, mean (SD), kg | 95.2 (18.7) | 95.3 (18.7) | 95.1 (18.7) |
| Height, mean (SD), cm | 167.4 (9.1) | 167.1 (8.8) | 167.6 (9.3) |
| Waist circumference, mean (SD), cm | 109.6 (13.7) | 110.1 (13.6) | 109.0 (13.8) |
| BMI, mean (SD) | 33.8 (5.2) | 34.0 (5.3) | 33.7 (5.1) |
| Blood pressure, mean (SD), mm Hg | |||
| Systolic | 121.1 (14.9) | 121.1 (14.3) | 121.2 (15.5) |
| Diastolic | 75.5 (11.0) | 74.9 (10.8) | 76.2 (11.2) |
| Heart rate, mean (SD), beats/min | 70.6 (10.7) | 70.5 (10.1) | 70.8 (11.3) |
| Flexibility, mean (SD), cm | |||
| Sit and reachc | −3.3 (9.4) | −3.9 (9.4) | −2.6 (9.5) |
| Aerobic stamina, mean (SD) | |||
| 1-Minute sit to stand, No. of stands | 27.5 (7.9) | 27.8 (8.0) | 27.3 (7.7) |
| 6-Minute walk, md | 528.1 (67.1) | 526.1 (61.5) | 530.2 (72.5) |
| Oxford Happiness Questionnaire total score, mean (SD)e | 4.2 (0.7) | 4.2 (0.7) | 4.2 (0.7) |
| Impact of Weight on Quality of Life–Lite score, mean (SD)f | |||
| Total | 73.0 (19.3) | 73.7 (20.2) | 72.4 (18.2) |
| Physical function | 50.8 (27.3) | 52.0 (27.6) | 49.6 (27.1) |
| Self-esteem | 71.8 (27.6) | 72.5 (28.2) | 71.1 (27.0) |
| Sexual life | 84.9 (19.7) | 83.9 (21.0) | 85.9 (18.4) |
| Public distress | 82.7 (19.2) | 81.7 (20.8) | 83.7 (17.5) |
| Work | 71.0 (17.8) | 71.3 (18.5) | 70.7 (17.1) |
| Pittsburg Sleep Quality Index score, mean (SD)g | |||
| Total | 6.4 (3.2) | 6.3 (3.3) | 6.6 (3.2) |
| Duration of sleep | 0.7 (0.8) | 0.7 (0.8) | 0.7 (0.8) |
| Sleep disturbance | 1.3 (0.5) | 1.3 (0.5) | 1.3 (0.6) |
| Sleep latency | 1.1 (1.0) | 1.0 (0.9) | 1.2 (1.0) |
| Day dysfunction due to sleepiness | 1.0 (0.7) | 1.0 (0.7) | 1.1 (0.8) |
| Sleep efficiency | 0.8 (1.0) | 0.8 (1.0) | 0.8 (1.0) |
| Overall sleep quality | 1.2 (0.7) | 1.2 (0.7) | 1.3 (0.7) |
| Need medication to sleep | 0.3 (0.7) | 0.3 (0.8) | 0.2 (0.7) |
Abbreviations: A level, General Certificate of Education Advanced Level; BMI, body mass index (calculated as weight in kilograms divided by height in meters squared); DIY, do-it-yourself; GCSE, General Certificate of Secondary Education; GED, General Educational Development Certification.
Racial and ethnic minority group was self-reported in the UK and categorized as racial and ethnic minority group in the US and Canada if reported as anything other than White and not Hispanic or Latino.
Data were missing for 1 patient in the commercial weight loss program group.
Flexibility was measured using the Sit and Reach Test. A measurement of 0 cm means the participant was able to touch their toes.
The 6-minute walk was not measured among the UK participants (62 in the commercial weight management program and 63 in the DIY group) because of a lack of space to conduct the measurement in the clinic.
Oxford Happiness Questionnaire is a 29-item instrument that is self-administered and uses a 6-point response format. Scores range from 1 (strongly disagree) to 6 (strongly agree). The overall happiness score is the mean.
Impact of Weight on Quality of Life–Lite is a 31-item instrument. The overall score and the 5 subscale scores are calculated as the mean scores from the 5-point response format, where 1 indicates never true and 5 indicates always true.
Pittsburgh Sleep Quality Index assesses participant’s usual sleep habits during the past month. Participants receive scores between 0 and 3 (where 0 is better) for 7 sleep categories. Total score ranges from 0 (better) to 21 (worse); a score of less than 5 is associated with good sleep quality, and a score of 5 or more is associated with poor sleep quality.
Secondary outcomes were analyzed using the same approach as for the primary outcomes, with the exception that imputation of missing data was not applied. The primary outcome variables were also analyzed without imputation as secondary outcomes (completers). The study was not powered for country-specific analyses; thus, no statistical tests were conducted at the country level. All analyses were conducted in SAS, version 9.4 (SAS Institute Inc) by investigators (K.P.T. and J.S.) who were not involved in the study intervention or assessments. All P values were from 2-sided tests, and results were deemed statistically significant at P < .03.
Results
Sample Characteristics
Among 3353 adults who demonstrated initial interest in participation, 373 were randomized (186 to the DIY group, and 187 to the commercial weight management program; 272 women [72.9%]; mean [SD] BMI, 33.8 [5.2]; 106 [28.4%] from underrepresented racial and ethnic groups; 77 [20.6%] aged 18-34 years, 74 [19.8%] aged 35-43 years, 82 [22.0%] aged 44-52 years, and 140 [37.5%] aged 53-75 years) (Table 1). There were no significant differences between randomized groups on any baseline characteristic. The retention rate for the commercial program group was 94.7% (177 of 187) at 3 months and 88.8% (166 of 187) at 12 months, and the retention rate for the DIY group was 98.4% (183 of 186) at 3 months and 95.7% (178 of 186) at 12 months (Figure 1). The retention rate in the DIY group was significantly higher at both time points (P = .05 at 3 months and P = .01 at 12 months, determined by the χ2 test).
Primary Outcomes
Figure 2 shows the adjusted 97.5% CIs around the differences in weight change between the groups at 3 and 12 months. Intention-to-treat analyses with multiple imputation showed that participants in the commercial program group had a mean (SD) weight loss at 3 months of −3.8 (4.1) kg vs −1.8 (3.7) kg in the DIY group and a mean (SD) weight loss at 12 months of −4.4 (7.3) kg vs −1.7 (7.3) kg in the DIY group. As hypothesized, commercial program participants had significantly greater weight loss at 3 months (mean difference, −2.0 kg [97.5% CI, −2.9 to −1.1 kg]) and 12 months (mean difference, −2.6 kg [97.5% CI, −4.3 to −0.8 kg]) (Figure 2). Results by completers and multiple imputation showed identical patterns of significance (eTable 1 in Supplement 2).
Figure 2. Weight Losses by Study Group at 3 and 12 Months.
Error bars indicate 97.5% CIs. DIY indicates do-it-yourself.
Secondary Outcomes
Differences in weight change between the groups persisted when examining only completers (Table 2). At 3 and 12 months, participants in the commercial program group experienced a significantly larger percentage weight loss than those in the DIY group (difference: 3 months, –2.3% [97.5% CI, –3.2% to –1.4%]; 12 months, −2.8% [97.5% CI, −4.5% to −1.1%]) and reductions in waist circumference (difference: 3 months, –2.0 cm [97.5% CI, –3.7 to –0.4 cm]; 12 months, –3.1 cm [97.5% CI, –5.2 to –1.0 cm]) than participants in the DIY group. At 3 months, more participants in the commercial program group than in the DIY group lost 5% of body weight (40.7% [72 of 177] vs 18.6% [34 of 183]; relative risk, 2.13 [97.5% CI 1.44-3.17]), and that difference persisted at 12 months (42.8% [71 of 166] in the commercial program group vs 24.7% [44 of 178] in the DIY group; relative risk, 1.73 [97.5% CI, 1.22-2.47]).
Table 2. Mean Difference Between Study Groups in Predefined Secondary Outcomes Among Completers.
| Outcome | Change, mean (SD)a | Difference (97.5% CI)b | P value | |
|---|---|---|---|---|
| DIY group | Commercial weight management program group | |||
| 3-Month secondary outcomes | ||||
| Weight change, % | −1.81 (3.89) | −4.12 (4.13) | −2.29 (−3.20 to −1.37) | <.001 |
| Waist circumference, cm | −2.10 (6.55) | −4.12 (7.55) | −2.03 (−3.70 to −0.36) | .007 |
| Blood pressure, mm Hg | ||||
| Systolic | 0.60 (8.50) | −0.80 (9.04) | −1.07 (−3.66 to 1.52) | .36 |
| Diastolic | 0.07 (10.85) | −1.07 (11.25) | −1.34 (−3.41 to 0.73) | .15 |
| Heart rate, beats/min | −0.54 (8.45) | −1.71 (8.86) | −1.13 (−3.19 to 0.93) | .22 |
| Flexibility | ||||
| Sit and reach distance, cm | 2.40 (4.19) | 2.64 (4.38) | 0.24 (−0.78 to 1.26) | .59 |
| Aerobic stamina | ||||
| 1-Minute sit to stand, No. of stands | 2.07 (5.98) | 3.11 (5.51) | 1.07 (−0.29 to 2.42) | .08 |
| 6-Minute walk, m | 6.76 (41.74) | 13.14 (43.10) | 6.34 (−6.09 to 18.78) | .25 |
| Oxford Happiness Questionnaire score | −0.03 (0.51) | 0.05 (0.50) | 0.08 (−0.04 to 0.19) | .15 |
| Pittsburgh Sleep Quality Index score | ||||
| Total | −0.09 (2.69) | −0.49 (2.59) | −0.39 (−1.02 to 0.23) | .16 |
| Duration of sleep | −0.03 (0.76) | −0.03 (0.79) | 0.01 (−0.18 to 0.19) | .93 |
| Sleep disturbance | 0.03 (0.55) | −0.06 (0.52) | −0.09 (−0.22 to 0.04) | .11 |
| Sleep latency | 0.03 (0.81) | −0.14 (0.83) | −0.17 (−0.37 to 0.02) | .05 |
| Day dysfunction due to sleepiness | −0.04 (0.70) | −0.15 (0.63) | −0.10 (−0.26 to 0.06) | .15 |
| Sleep efficiency | −0.02 (1.11) | 0.06 (1.08) | 0.07 (−0.19 to 0.34) | .52 |
| Overall sleep quality | −0.09 (0.67) | −0.20 (0.71) | −0.11 (−0.28 to 0.05) | .12 |
| Need medication to sleep | 0.04 (0.63) | 0.04 (0.62) | 0.00 (−0.15 to 0.15) | .99 |
| Impact of Weight on Quality of Life score | ||||
| Total | 5.11 (10.32) | 7.58 (10.62) | 2.49 (0.03 to 4.95) | .02 |
| Physical function | 5.17 (12.57) | 9.28 (13.01) | 4.10 (1.08 to 7.13) | .002 |
| Self-esteem | 7.49 (17.98) | 10.84 (16.50) | 3.46 (−0.57 to 7.48) | .05 |
| Sexual life | 4.32 (19.39) | 6.39 (20.81) | 1.97 (−2.83 to 6.78) | .36 |
| Public distress | 2.76 (12.12) | 3.53 (12.39) | 0.79 (−2.13 to 3.70) | .55 |
| Work | 4.61 11.90) | 3.64 (12.22) | −0.97 (−3.84 to 1.90) | .83 |
| 12-Month secondary outcomes | ||||
| Weight change, % | −1.93 (7.21) | −4.68 (7.33) | −2.80 (−4.54 to −1.05) | <.001 |
| Waist circumference, cm | −2.70 (8.70) | −5.70 (8.85) | −3.10 (−5.23 to −0.97) | .001 |
| Blood pressure, mm Hg | ||||
| Systolic | −0.68 (8.39) | −1.39 (9.45) | 0.19 (−2.57 to 2.95) | .88 |
| Diastolic | −1.70 (11.01) | −1.57 (11.39) | −0.72 (−2.93 to 1.49) | .46 |
| Heart rate, beats/min | 0.47 (9.07) | −0.32 (8.81) | −0.73 (−2.94 to 1.47) | .46 |
| Flexibility | ||||
| Sit and reach distance, cm | 1.97 (5.56) | 2.99 (5.66) | 1.06 (−0.35 to 2.48) | .09 |
| Aerobic stamina | ||||
| 1-Minute sit to stand, No. of stands | 3.39 (6.98) | 3.49 (6.24) | 0.16 (−1.47 to 1.80) | .82 |
| 6-Minute walk test, m | −4.97 (58.04) | −2.04 (79.61) | 2.88 (−17.01 to 22.76) | .74 |
| Oxford Happiness Questionnaire score | 0.05 (0.61) | 0.09 (0.57) | 0.04 (−0.10 to 0.18) | .52 |
| Pittsburgh Sleep Quality Index score | ||||
| Total | 0.21 (2.98) | −0.31 (2.61) | −0.55 (−1.23 to 0.14) | .07 |
| Duration of sleep | 0.04 (0.81) | −0.07 (0.79) | −0.11 (−0.30 to 0.09) | .22 |
| Sleep disturbance | 0.02 (0.55) | 0.02 (0.55) | 0.00 (−0.13 to 0.14) | .94 |
| Sleep latency | −0.02 (0.77) | −0.12 (0.82) | −0.10 (−0.29 to 0.09) | .25 |
| Day dysfunction due to sleepiness | −0.07 (0.78) | −0.12 (0.76) | −0.05 (−0.24 to 0.14) | .55 |
| Sleep efficiency | 0.23 (1.22) | 0.02 (1.18) | −0.21 (−0.50 to 0.08) | .10 |
| Overall sleep quality | −0.04 (0.70) | −0.10 (0.65) | −0.06 (−0.22 to 0.11) | .43 |
| Need medication to sleep | 0.07 (0.76) | 0.04 (0.71) | −0.02 (−0.20 to 0.15) | .76 |
| Impact of Weight on Quality of Life score | ||||
| Total | 5.96 (12.28) | 8.43 (11.83) | 2.54 (−0.38 to 5.45) | .05 |
| Physical function | 5.76 (14.00) | 8.72 (14.17) | 3.04 (−0.37 to 6.46) | .05 |
| Self-esteem | 8.23 (19.29) | 13.23 (20.36) | 5.14 (0.37 to 9.91) | .02 |
| Sexual life | 5.70 (22.73) | 8.56 (21.53) | 2.88 (−2.54 to 8.30) | .23 |
| Public distress | 3.26 (12.80) | 3.34 (13.95) | 0.10 (−3.15 to 3.36) | .73 |
| Work | 5.90 (15.01) | 5.53 (12.81) | −0.38 (−3.78 to 3.02) | .80 |
Abbreviation: DIY, do-it-yourself.
Unadjusted mean values.
Model-estimated difference (commercial program − DIY) adjusted for site, sex, and minority status. Differences were significant at P < .03.
Although both groups experienced improvements in blood pressure, aerobic stamina, flexibility, and happiness at 3 and 12 months, there were no significant differences between groups. At 3 months, participants in the commercial program group had significantly greater improvements than those in the DIY group (total score, 2.49 [97.5% CI, 0.03-4.95]; P = .02; and physical function subscale, 4.10 [97.5% CI 1.08-7.13]; P = .02). At 12 months, only the difference in improvements on the self-esteem subscale was significant (5.14 [97.5% CI, 0.37-9.91]; P = .02).
Commercial Weight Management Program Engagement
During the first 3 months, 75.4% of those randomly assigned to the commercial program (141 of 187) used the app and attended workshops, 19.8% (37 of 187) used only the app, no participants attended only workshops, and 4.8% (9 of 187) did not engage in the workshops or use the app (eTable 2 in Supplement 2). The mean (SD) number of meetings attended during the first 3 months was 5.5 (4.5) (approximately 2 per month), and participants used the app a mean (SD) of 50.8 (29.5) days (approximately 4 logins per week). Although participation decreased between months 3 and 12, 81.3% (152 of 187) continued engaging in the program at some level (with mean [SD] attendance of approximately 1.0 [1.5] meeting per month and 2.4 [2.6] logins per week).
DIY Engagement
The DIY group reported limited use of commercial programs (1.7% [3 of 178]) and limited use of other formal weight loss support groups (3.4% [6 of 178]) (eTable 3 in Supplement 2). The most popular strategies were using their own approach without following any published diet (71.4% [127 of 178]), using a weight loss app on a smartphone (38.2% [68 of 178]), losing weight with a friend or family member (24.7% [44 of 178]), and using structured exercise classes or a personal trainer (19.7% [35 of 178]).
Response to Treatment
Among commercial weight management program participants, attendance at workshops (r = −0.565; P < .001) and number of days of app use (r = −0.622; P < .001) were significantly correlated with 12-month weight loss (Table 3). In models adjusted for sex, race and ethnicity, and site, each workshop attended was associated with 0.24 kg (97.5% CI, 0.18-0.31 kg) greater weight loss at 12 months, and each app login day was associated with an additional 0.04 kg (97.5% CI, 0.03-0.04 kg) greater weight loss at 12 months. In other words, every 4 meetings attended and/or every 25 days of app use were associated with an additional kilogram of weight loss.
Table 3. Weight Change by Participation in Commercial Weight Management Programa.
| Absolute weight change | Mean weight change per 1 in-person session or app login (97.5% CI) | Correlations between weight change and intervention dose | ||||||
|---|---|---|---|---|---|---|---|---|
| Weight change per 1 in-person session attended, kg | P value | Weight change per app login (day), kg | P value | Correlation with in-person sessions attended | P value | Correlation with app login (day) | P value | |
| At 0-3 mo | −0.5 (−0.6 to −0.3) | <.001 | −0.1 (−0.1 to −0.06) | <.001 | −0.477 | <.001 | −0.540 | <.001 |
| At 0-12 mo | −0.2 (−0.3 to −0.2) | <.001 | −0.04 (−0.04 to −0.03) | <.001 | −0.565 | <.001 | −0.622 | <.001 |
Model adjusted for site, sex, and minority status.
Discussion
This 3-country randomized clinical trial revealed that at 3 and 12 months, compared with individuals randomly assigned to a DIY weight loss method, those randomly assigned to the commercial weight management program had greater reductions in weight and waist circumference and a greater percentage achieved a 5% weight loss. These changes are clinically meaningful, having been consistently associated with improvements in multiple health conditions.3,36,37,38 Although many secondary outcomes improved among participants in both groups (blood pressure, heart rate, aerobic stamina, flexibility, and sleep), those changes were not significantly different between the groups at 3 or 12 months. Failure to detect changes in some of these physiological measures, such as blood pressure, despite the level of weight loss achieved, is consistent with other studies39 and may be related to the fact that the sample was relatively healthy at baseline (eg, blood pressure of 121/76 mm Hg; Table 1).
One of the key features of the commercial program evaluated in this study was that self-monitoring was simplified to be less burdensome. Participants did not need to weigh, measure, or track more than 200 foods. This larger randomized clinical trial across 3 countries yielded results similar to those found in a single-group pilot study25 of this approach and suggests that programs with lower demands for self-monitoring can produce clinically significant weight loss. Future studies should compare partial self-monitoring approaches with traditional monitoring of all foods and their effect on weight loss to isolate the mechanisms of action as well as other methods of partial self-monitoring.
Participation in the commercial program intervention, both in app use and in-person sessions, was associated with weight loss, as previously shown in both community15,40 and clinical settings.41,42,43 Consistent with other studies, attendance at in-person sessions and login rates decreased during months 3 to 12 compared with the initial period,2,44,45,46 but this decrease was not associated with weight regain, and a greater proportion of the overall sample achieved a loss of 5% of body weight at 12 vs 3 months. Few participants in the DIY group used commercial programs, and the most common DIY method was their own approach (71.4%), followed by the use of a weight loss app on a smartphone (38.2%) and losing weight with a friend or family member (24.7%). Thus, the comparison between the commercial program and the DIY group seems consistent with the intended design.
Strengths and Limitations
This study has several strengths that contribute to internal validity, including the randomized clinical trial design, blinded assessors, separate intervention and assessment staff, initial and longer-term outcomes, objective measures of commercial program app engagement, and strong retention rates over 12 months. Study strengths that contribute to external validity included a more diverse population than typical in commercial weight management program evaluations, inclusion of participants in multiple countries, and a realistic comparator (DIY approach). Differences between groups may have been larger if a no-treatment control had been used, but the DIY comparator has strong relevance because it is feasible and often used in community and health settings. In addition, the commercial program intervention is publicly available in the 3 countries studied and is a program implemented by staff who were not part of this research.
The study also has some limitations. Sample sizes within each country did not permit a statistically powerful analysis by country, participants in the DIY group may have postponed weight loss efforts until receipt of the commercial program at 12 months, and we had no outcome data beyond 1 year to assess longer-term efficacy. Secondary outcomes were considered exploratory, and additional corrections for multiplicity were not applied. Finally, despite strong retention rates, more DIY participants attended the 3- and 12-month follow-up.
Conclusions
In this randomized clinical trial, adults randomly assigned to a widely available commercial weight management program had greater reductions in weight and were more likely to achieve a 5% weight loss than those randomly assigned to a DIY approach. The results suggest that health care professionals might discuss the potential merits of commercial programs compared with efforts patients might undertake to lose weight on their own for greater likelihood of clinical benefit. The results of this trial also offer initial insights into ways in which dietary monitoring, a key behavior change tool, can be simplified while retaining efficacy.
Trial Protocol
eMethods.
eTable 1. Mean Difference (97.5% CI) in the 3-Month and 12-Month Absolute (Primary) and Percent (Secondary) Weight Change Overall in Completers and After Multiple Imputation
eTable 2. Commercial Weight Management Program Intervention Participation
eTable 3. Self-reported Weight Loss Approaches by DIY Group
Data Sharing Statement
References
- 1.Expert Panel on the Identification, Evaluation, and Treatment of Overweight and Obesity in Adults. Executive summary of the clinical guidelines on the identification, evaluation, and treatment of overweight and obesity in adults. Arch Intern Med. 1998;158(17):1855-1867. doi: 10.1001/archinte.158.17.1855 [DOI] [PubMed] [Google Scholar]
- 2.Curry SJ, Krist AH, Owens DK, et al. ; US Preventive Services Task Force . Behavioral weight loss interventions to prevent obesity-related morbidity and mortality in adults: US Preventive Services Task Force recommendation statement. JAMA. 2018;320(11):1163-1171. doi: 10.1001/jama.2018.13022 [DOI] [PubMed] [Google Scholar]
- 3.Jensen MD, Ryan DH, Apovian CM, et al. ; American College of Cardiology/American Heart Association Task Force on Practice Guidelines; Obesity Society . 2013 AHA/ACC/TOS guideline for the management of overweight and obesity in adults: a report of the American College of Cardiology/American Heart Association Task Force on Practice Guidelines and the Obesity Society. Circulation. 2014;129(25)(suppl 2):S102-S138. doi: 10.1161/01.cir.0000437739.71477.ee [DOI] [PMC free article] [PubMed] [Google Scholar]
- 4.Garvey WT, Mechanick JI, Brett EM, et al. ; Reviewers of the AACE/ACE Obesity Clinical Practice Guidelines . American Association of Clinical Endocrinologists and American College of Endocrinology comprehensive clinical practice guidelines for medical care of patients with obesity. Endocr Pract. 2016;22(suppl 3):1-203. doi: 10.4158/EP161365.GL [DOI] [PubMed] [Google Scholar]
- 5.Wadden TA, Webb VL, Moran CH, Bailer BA. Lifestyle modification for obesity: new developments in diet, physical activity, and behavior therapy. Circulation. 2012;125(9):1157-1170. doi: 10.1161/CIRCULATIONAHA.111.039453 [DOI] [PMC free article] [PubMed] [Google Scholar]
- 6.Wojtanowski AC, Foster GD. Scaling science-based approaches beyond the clinic. In: Morton JM, Brethauer SA, DeMaria EJ, Kahan S, Hutter MM, eds. Quality in Obesity Treatment. Springer International Publishing; 2019:117-128. [Google Scholar]
- 7.Gudzune KA, Doshi RS, Mehta AK, et al. Efficacy of commercial weight-loss programs: an updated systematic review. Ann Intern Med. 2015;162(7):501-512. doi: 10.7326/M14-2238 [DOI] [PMC free article] [PubMed] [Google Scholar]
- 8.Gudzune KA, Clark JM. Role of commercial weight-loss programs in medical management of obesity. Endocrinol Metab Clin North Am. 2020;49(2):275-287. doi: 10.1016/j.ecl.2020.02.006 [DOI] [PubMed] [Google Scholar]
- 9.Laudenslager M, Chaudhry ZW, Rajagopal S, Clynes S, Gudzune KA. Commercial weight loss programs in the management of obesity: an update. Curr Obes Rep. 2021;10(2):90-99. doi: 10.1007/s13679-021-00428-y [DOI] [PMC free article] [PubMed] [Google Scholar]
- 10.Finkelstein EA, Kruger E. Meta- and cost-effectiveness analysis of commercial weight loss strategies. Obesity (Silver Spring). 2014;22(9):1942-1951. doi: 10.1002/oby.20824 [DOI] [PubMed] [Google Scholar]
- 11.Finkelstein EA, Verghese NR. Incremental cost-effectiveness of evidence-based non-surgical weight loss strategies. Clin Obes. 2019;9(2):e12294. doi: 10.1111/cob.12294 [DOI] [PubMed] [Google Scholar]
- 12.Heshka S, Anderson JW, Atkinson RL, et al. Weight loss with self-help compared with a structured commercial program: a randomized trial. JAMA. 2003;289(14):1792-1798. doi: 10.1001/jama.289.14.1792 [DOI] [PubMed] [Google Scholar]
- 13.Ahern AL, Wheeler GM, Aveyard P, et al. Extended and standard duration weight-loss programme referrals for adults in primary care (WRAP): a randomised controlled trial. Lancet. 2017;389(10085):2214-2225. doi: 10.1016/S0140-6736(17)30647-5 [DOI] [PMC free article] [PubMed] [Google Scholar]
- 14.Pinto AM, Fava JL, Hoffmann DA, Wing RR. Combining behavioral weight loss treatment and a commercial program: a randomized clinical trial. Obesity (Silver Spring). 2013;21(4):673-680. doi: 10.1002/oby.20044 [DOI] [PMC free article] [PubMed] [Google Scholar]
- 15.Johnston CA, Rost S, Miller-Kovach K, Moreno JP, Foreyt JP. A randomized controlled trial of a community-based behavioral counseling program. Am J Med. 2013;126(12):1143.e19-1143.e24. doi: 10.1016/j.amjmed.2013.04.025 [DOI] [PubMed] [Google Scholar]
- 16.Jebb SA, Ahern AL, Olson AD, et al. Primary care referral to a commercial provider for weight loss treatment versus standard care: a randomised controlled trial. Lancet. 2011;378(9801):1485-1492. doi: 10.1016/S0140-6736(11)61344-5 [DOI] [PMC free article] [PubMed] [Google Scholar]
- 17.Klem ML, Wing RR, McGuire MT, Seagle HM, Hill JO. A descriptive study of individuals successful at long-term maintenance of substantial weight loss. Am J Clin Nutr. 1997;66(2):239-246. doi: 10.1093/ajcn/66.2.239 [DOI] [PubMed] [Google Scholar]
- 18.Burke LE, Warziski M, Starrett T, et al. Self-monitoring dietary intake: current and future practices. J Ren Nutr. 2005;15(3):281-290. doi: 10.1016/j.jrn.2005.04.002 [DOI] [PubMed] [Google Scholar]
- 19.Wang J, Sereika SM, Chasens ER, Ewing LJ, Matthews JT, Burke LE. Effect of adherence to self-monitoring of diet and physical activity on weight loss in a technology-supported behavioral intervention. Patient Prefer Adherence. 2012;6:221-226. doi: 10.2147/PPA.S28889 [DOI] [PMC free article] [PubMed] [Google Scholar]
- 20.Burke LE, Swigart V, Warziski Turk M, Derro N, Ewing LJ. Experiences of self-monitoring: successes and struggles during treatment for weight loss. Qual Health Res. 2009;19(6):815-828. doi: 10.1177/1049732309335395 [DOI] [PMC free article] [PubMed] [Google Scholar]
- 21.Krukowski RA, Harvey J, Borden J, Stansbury ML, West DS. Expert opinions on reducing dietary self-monitoring burden and maintaining efficacy in weight loss programs: a Delphi study. Obes Sci Pract. Published online January 12, 2022. doi: 10.1002/osp4.586 [DOI] [PMC free article] [PubMed] [Google Scholar]
- 22.Burke LE, Styn MA, Sereika SM, et al. Using mHealth technology to enhance self-monitoring for weight loss: a randomized trial. Am J Prev Med. 2012;43(1):20-26. doi: 10.1016/j.amepre.2012.03.016 [DOI] [PMC free article] [PubMed] [Google Scholar]
- 23.Burke LE, Wang J, Sevick MA. Self-monitoring in weight loss: a systematic review of the literature. J Am Diet Assoc. 2011;111(1):92-102. doi: 10.1016/j.jada.2010.10.008 [DOI] [PMC free article] [PubMed] [Google Scholar]
- 24.Boutelle KN, Kirschenbaum DS. Further support for consistent self-monitoring as a vital component of successful weight control. Obes Res. 1998;6(3):219-224. doi: 10.1002/j.1550-8528.1998.tb00340.x [DOI] [PubMed] [Google Scholar]
- 25.Tate DF, Quesnel DA, Lutes L, et al. Examination of a partial dietary self-monitoring approach for behavioral weight management. Obes Sci Pract. 2020;6(4):353-364. doi: 10.1002/osp4.416 [DOI] [PMC free article] [PubMed] [Google Scholar]
- 26.Wing RR, Phelan S. Long-term weight loss maintenance. Am J Clin Nutr. 2005;82(1)(suppl):222S-225S. doi: 10.1093/ajcn/82.1.222S [DOI] [PubMed] [Google Scholar]
- 27.Mifflin MD, St Jeor ST, Hill LA, Scott BJ, Daugherty SA, Koh YO. A new predictive equation for resting energy expenditure in healthy individuals. Am J Clin Nutr. 1990;51(2):241-247. doi: 10.1093/ajcn/51.2.241 [DOI] [PubMed] [Google Scholar]
- 28.Harvey LA. REDCap: web-based software for all types of data storage and collection. Spinal Cord. 2018;56(7):625. doi: 10.1038/s41393-018-0169-9 [DOI] [PubMed] [Google Scholar]
- 29.Centers for Disease Control and Prevention. NHANES 2019-2020 procedure manuals. Accessed December 7, 2020. https://wwwn.cdc.gov/nchs/nhanes/continuousnhanes/manuals.aspx?BeginYear=2019
- 30.Ferguson B. ACSM’s Guidelines for Exercise Testing and Prescription 9th ed. 2014. J Can Chiropr Assoc. 2014;58(3):328. [Google Scholar]
- 31.ATS Committee on Proficiency Standards for Clinical Pulmonary Function Laboratories . ATS statement: guidelines for the six-minute walk test. Am J Respir Crit Care Med. 2002;166(1):111-117. doi: 10.1164/ajrccm.166.1.at1102 [DOI] [PubMed] [Google Scholar]
- 32.Hills P, Argyle M. The Oxford Happiness Questionnaire: a compact scale for the measurement of psychological well-being. Pers Individ Dif. 2002;33(7):1073-1082. doi: 10.1016/S0191-8869(01)00213-6 [DOI] [Google Scholar]
- 33.Buysse DJ, Reynolds CF III, Monk TH, Berman SR, Kupfer DJ. The Pittsburgh Sleep Quality Index: a new instrument for psychiatric practice and research. Psychiatry Res. 1989;28(2):193-213. doi: 10.1016/0165-1781(89)90047-4 [DOI] [PubMed] [Google Scholar]
- 34.Carpenter JS, Andrykowski MA. Psychometric evaluation of the Pittsburgh Sleep Quality Index. J Psychosom Res. 1998;45(1):5-13. doi: 10.1016/S0022-3999(97)00298-5 [DOI] [PubMed] [Google Scholar]
- 35.Kolotkin RL, Crosby RD, Kosloski KD, Williams GR. Development of a brief measure to assess quality of life in obesity. Obes Res. 2001;9(2):102-111. doi: 10.1038/oby.2001.13 [DOI] [PubMed] [Google Scholar]
- 36.Knowler WC, Fowler SE, Hamman RF, et al. ; Diabetes Prevention Program Research Group . 10-Year follow-up of diabetes incidence and weight loss in the Diabetes Prevention Program Outcomes Study. Lancet. 2009;374(9702):1677-1686. doi: 10.1016/S0140-6736(09)61457-4 [DOI] [PMC free article] [PubMed] [Google Scholar]
- 37.Ryan DH, Yockey SR. Weight loss and improvement in comorbidity: differences at 5%, 10%, 15%, and over. Curr Obes Rep. 2017;6(2):187-194. doi: 10.1007/s13679-017-0262-y [DOI] [PMC free article] [PubMed] [Google Scholar]
- 38.Magkos F, Fraterrigo G, Yoshino J, et al. Effects of moderate and subsequent progressive weight loss on metabolic function and adipose tissue biology in humans with obesity. Cell Metab. 2016;23(4):591-601. doi: 10.1016/j.cmet.2016.02.005 [DOI] [PMC free article] [PubMed] [Google Scholar]
- 39.Ge L, Sadeghirad B, Ball GDC, et al. Comparison of dietary macronutrient patterns of 14 popular named dietary programmes for weight and cardiovascular risk factor reduction in adults: systematic review and network meta-analysis of randomised trials. BMJ. 2020;369:m696. doi: 10.1136/bmj.m696 [DOI] [PMC free article] [PubMed] [Google Scholar]
- 40.Johnston CA, Moreno JP, Hernandez DC, et al. Levels of adherence needed to achieve significant weight loss. Int J Obes (Lond). 2019;43(1):125-131. doi: 10.1038/s41366-018-0226-7 [DOI] [PubMed] [Google Scholar]
- 41.Hollis JF, Gullion CM, Stevens VJ, et al. ; Weight Loss Maintenance Trial Research Group . Weight loss during the intensive intervention phase of the weight-loss maintenance trial. Am J Prev Med. 2008;35(2):118-126. doi: 10.1016/j.amepre.2008.04.013 [DOI] [PMC free article] [PubMed] [Google Scholar]
- 42.Tronieri JS, Wadden TA, Walsh O, Berkowitz RI, Alamuddin N, Chao AM. Measures of adherence as predictors of early and total weight loss with intensive behavioral therapy for obesity combined with liraglutide 3.0 mg. Behav Res Ther. 2020;131:103639. doi: 10.1016/j.brat.2020.103639 [DOI] [PMC free article] [PubMed] [Google Scholar]
- 43.Acharya SD, Elci OU, Sereika SM, et al. Adherence to a behavioral weight loss treatment program enhances weight loss and improvements in biomarkers. Patient Prefer Adherence. 2009;3:151-160. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 44.Michie S, Abraham C, Whittington C, McAteer J, Gupta S. Effective techniques in healthy eating and physical activity interventions: a meta-regression. Health Psychol. 2009;28(6):690-701. doi: 10.1037/a0016136 [DOI] [PubMed] [Google Scholar]
- 45.McVay MA, Bennett GG, Steinberg D, Voils CI. Dose-response research in digital health interventions: concepts, considerations, and challenges. Health Psychol. 2019;38(12):1168-1174. doi: 10.1037/hea0000805 [DOI] [PMC free article] [PubMed] [Google Scholar]
- 46.Bartfield JK, Stevens VJ, Jerome GJ, et al. Behavioral transitions and weight change patterns within the PREMIER Trial. Obesity (Silver Spring). 2011;19(8):1609-1615. doi: 10.1038/oby.2011.56 [DOI] [PMC free article] [PubMed] [Google Scholar]
Associated Data
This section collects any data citations, data availability statements, or supplementary materials included in this article.
Supplementary Materials
Trial Protocol
eMethods.
eTable 1. Mean Difference (97.5% CI) in the 3-Month and 12-Month Absolute (Primary) and Percent (Secondary) Weight Change Overall in Completers and After Multiple Imputation
eTable 2. Commercial Weight Management Program Intervention Participation
eTable 3. Self-reported Weight Loss Approaches by DIY Group
Data Sharing Statement


