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Commercial Web-based weight-loss programs are becoming more popular and increasingly refined through the addition of enhanced features, yet few randomized controlled trials (RCTs) have independently and rigorously evaluated the efficacy of these commercial programs or additional features.
To determine whether overweight and obese adults randomized to an online weight-loss program with additional support features (enhanced) experienced a greater reduction in body mass index (BMI) and increased usage of program features after 12 and 24 weeks compared to those randomized to a standard online version (basic).
An assessor-blinded RCT comparing 301 adults (male: n=125, 41.5%; mean age: 41.9 years, SD 10.2; mean BMI: 32.2 kg/m2, SD 3.9) who were recruited and enrolled offline, and randomly allocated to basic or enhanced versions of a commercially available Web-based weight-loss program for 24 weeks.
Retention at 24 weeks was greater in the enhanced group versus the basic group (basic 68.5%, enhanced 81.0%;
The addition of personalized e-feedback in the enhanced program provided limited additional benefits compared to a standard commercial Web-based weight-loss program. However, it does support greater retention in the program and greater usage, which was related to weight loss. Further research is required to develop and examine Web-based features that may enhance engagement and outcomes and identify optimal usage patterns to enhance weight loss using Web-based programs.
Australian New Zealand Clinical Trials Registry (ANZCTR) trial number: ACTRN12610000197033; https://www.anzctr.org.au/Trial/Registration/TrialReview.aspx?id=335159 (Archived by WebCite at http://www.webcitation.org/6HoOMGb8j).
Internationally, obesity rates in adults continue to rise unabated [
A systematic review of the effectiveness of Web-based weight loss and maintenance interventions found that these programs can facilitate meaningful weight change [
Within the currently available online commercial weight-loss programs, there is a large degree of variation across the range of features provided, including blogs, chat rooms, self-monitoring tools for weight, diet, and physical activity, and also differing types and amounts of feedback from generic to tailored information and human e-counseling. To date, the ability of these more personalized enhanced features to facilitate greater weight loss has only had limited evaluation because programs have not tracked use of specific features [
We have previously compared the efficacy of a standard commercial Web-based weight-loss program (basic) versus an enhanced version of this Web program that provided additional personalized e-feedback and contact from the provider (enhanced) versus a waitlist control group [
This assessor-blinded RCT recruited overweight and obese adults from the Hunter community in New South Wales, Australia, who were enrolled offline in 2009. Eligibility criteria included age 18 to 60 years, BMI 25 to 40 kg/m2, not participating in other weight-loss programs, pass a health screen [
After baseline assessments were completed, participants were stratified by sex and BMI category (25 to <30, ≥30 to <35, or ≥35 to 40 kg/m2) and randomized using a stratified block design to either the standard (basic) Web-based weight-loss program or the same program with additional features (enhanced) (
Participant flow.
Participants were provided with free access to the basic or enhanced version of a commercial Web-based program provided by SP Health Co Pty Ltd in Australia under the name The Biggest Loser Club. The basic program was the version commercially available at the time of the study (2009-2010). Program features are reported in
The 12-week Web-based programs were based on social cognitive theory [
At the end of 12 weeks, participants could choose to repeat the same weekly 12-week program or to continue for an additional 12 weeks with content varied based on the season and keeping their entire accumulated personal progress and data.
The enhanced program included all the basic program features described previously. The additional components were: (1) personalized, system-generated enrollment reports that suggested appropriate weight-loss goals and key behavior changes required for success based on response to a behavioral survey at enrollment; (2) weekly automated system-generated, personalized e-feedback for key elements of diet and physical activity based on diary entries, usage patterns of website features, and level of success with weight loss (
Description of the basic and enhanced commercial Web-based weight-loss programs.
Basic and enhanced | Enhanced only |
Participants set weight-loss goals, advised to self-monitor their weight, waist, and hip girths. Encouraged to self-monitor via weekly email and/or short message service (SMS) text messaging reminders to enter weight on website. Entered data were tracked and displayed graphically and in a body (BMI) silhouette. | Personalized automated enrollment reports suggesting appropriate weight-loss goals and key behavior changes required for success. Eating behaviors targeted included total energy, saturated fat and fiber intake, daily servings of fruit and vegetables, high-risk eating behaviors (eg, skipping meals, not eating breakfast, drinking soft drinks) and nonhungry eating triggers. |
Individualized daily calorie targets to facilitate 0.5-1 kg weight loss per week (~2600 kJ less than their estimated energy requirements). | Weekly automated personalized feedback for key elements of diet and physical activity based on diary entries; usage patterns for website features; and level of success with weight loss. Eating behaviors targeted were consistent with the enrollment reports ( |
Access to weekly low-fat menu plan and grocery lists designed to meet nutrient reference values [ |
Reminders to use the online diary, visit the site, and/or weigh-in. The reminder schedule included an initial reminder email; if no response, a text message; if no response, a phone call. |
Web-based food and exercise diary to monitor energy intake and energy expenditure. Daily and weekly calculations of energy balance and nutrition summaries compared with recommended nutrient targets if food entries made in online diary. |
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Online education in the form of weekly tutorials, fact sheets, meal, and exercise plans and weekly challenges. |
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Social support via online discussion forums. |
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Participant assessments were conducted at the University of Newcastle at baseline, 12, and 24 weeks. Blinded research assistants conducted assessments for all groups, and participants were reminded at each assessment not to discuss group allocation.
Height was measured to 0.1 cm using the stretch stature method on a Harpenden portable stadiometer (Holtain Limited, Dyfed, UK). Weight was measured in light clothing, without shoes on a digital scale to 0.01 kg (CH-150kp, A&D Mercury Pty Ltd, Australia) and the primary outcome of BMI (kg/m2) calculated as weight (kg)/height (m)2. Waist circumference was measured to 0.1 cm using a nonextensible steel tape (KDSF10-02, KDS Corporation, Osaka, Japan) at 2 points: (1) level with the umbilicus and (2) at the narrowest point between the lower costal border and the umbilicus. Waist-to-height ratio was then calculated. Blood pressure and heart rate were measured using an automated blood pressure monitor (NISSEI/DS-105E digital electronic blood pressure monitor; Nihon Seimitsu Sokki Co Ltd, Gunma, Japan) under standardized conditions. Blood samples were collected with participants advised to fast overnight and analyzed for lipids (total cholesterol, low-density lipoprotein [LDL] and high-density lipoprotein [HDL], cholesterol, and triglycerides), glucose, and insulin using standard automated techniques at a single National Association of Testing Authorities accredited pathology service.
Dietary intake was assessed using the Australian Eating Survey (AES), a 120-item semiquantitative food-frequency questionnaire (FFQ). The AES has been evaluated for reliability and relative validity and demonstrates acceptable accuracy for ranking nutrient intakes in Australian adults [
The 18-item Three-Factor Eating Questionnaire-R18 (TFEQ-R18) was used to measure cognitive restraint, uncontrolled eating, and emotional eating [
The International Physical Activity Questionnaire-short form (IPAQ-SF) was used to estimate total metabolic equivalent (MET)-minutes/week [
Continuous data were summarized using descriptive statistics including mean (SD) and categorical data as category percentages. Demographic and baseline variables were compared between treatment groups using analysis of variance (ANOVA) for continuous variables and chi-square tests for categorical variables. Analysis of covariance (ANCOVA) was used to test for differences in outcomes at 12 weeks and 24 weeks between treatment groups after adjusting for the baseline value of that outcome. The model outcome was the variable of interest at 12 or 24 weeks with the baseline level used as a covariate. The only other variable included in the model was sex. Differences and 95% confidence intervals between treatment groups in the outcome at each time point were estimated using the least squares means from the ANCOVA models.
The intention-to-treat (ITT) population includes all participants who were randomized into 1 of the 2 treatment groups. For participants who had missing data at 12 or 24 weeks, their missing data was imputed using the last observation carried forward (LOCF) and baseline observation carried forward (BOCF) approach. The completer population includes all individuals who attended the 24-week assessment, and subgroup analyses are based on this population.
An additional analysis was conducted using a generalized linear mixed model (GLMM) to test for a difference between groups across the combined 12-week and 24-week time points. The outcome in this model was the individual’s outcome at the 2 posttreatment assessments; the main predictor of interest was treatment group with the baseline value of the outcome included as a covariate. Sex was also included as a covariate in these models because it is a common confounding factor. All analyses were programmed in Stata v11 or SAS v9.2 (StataCorp LP, College Station, TX, USA).
Enhanced groups weekly automated personalized feedback.
Of the 591 participants assessed for eligibility, 309 (129 males, 180 females) were initially randomized into the 3 groups (basic: n=99, enhanced: n=106, or waitlist control: n=104). After 12 weeks, the control group, of whom 8 were lost to follow-up, were rerandomized (96 participants, 52 enhanced, 44 basic) into the trial. Therefore, in the current analysis, 301 participants (125 males, 176 females) were randomized to the basic (n=143) or enhanced (n=158) groups (
Participants who were randomized to the basic group were similar at baseline to those randomized to the enhanced group for all demographic and other baseline characteristics (
Participant flow through the trial (
Weight, BMI, and waist circumference were significantly lower than baseline at 12 and 24 weeks in each group. Change in the primary outcome of BMI was similar between those randomized to the basic and enhanced groups at 12 and 24 weeks after treatment in the LOCF (
There was only 1 significant difference in secondary outcomes between the basic and enhanced groups in the LOCF (
The change in primary and secondary outcomes within treatment groups was similar across all subgroups (sex, age, BMI category) of the completer population at 12 or 24 weeks (data not presented). There were no statistically significant interactions between treatment group and sex (
There was a significantly greater website usage in the enhanced group compared to the basic group at both 12 and 24 weeks with the enhanced group logging on an additional 10 days over the first 12 weeks and 12 days over 24 weeks (
In the completers population, significant correlations were found between the percentage weight loss at 12 and 24 weeks and total website usage from baseline to 12 weeks (
Demographic and other baseline characteristics by treatment group.
Characteristic | Treatment group | Total |
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Basic |
Enhanced |
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Sex (male), n (%) | 59 (47.2) | 66 (52.8 ) | 125 (41.5 ) | .93 | |
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25 to <30 | 50 (46.7 ) | 57 (53.3 ) | 107 (35.5) | .97 |
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30 to <35 | 58 (48.3) | 62 (51.7) | 120 (39.9) |
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35 to <40 | 35 (47.3) | 39 (52.7) | 74 (24.6) |
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Current or previous smoker (never smoked), n (%) | 128 (47.8) | 140 (52.2) | 268 (89.0) | .91 | |
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High school | 43 (47.8) | 47 (52.2) | 90 (29.90) | .60 |
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Trade/diploma | 46 (44.2) | 58 (55.8) | 104 (34.6) |
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University degree | 37 (54.4) | 31 (45.60) | 68 (2.6) |
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Higher university degree | 17 (44.7) | 21 (55.3) | 38 (12.6) |
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<$700 | 12 (50.0) | 12 (50.0) | 24 (8.0) | .77 |
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$700 to <$1000 | 8 (50.0) | 8 (50.0) | 16 (5.6) |
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$1000 to <$1400 | 20 (57.1) | 15 (42.9) | 35 (11.6) |
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≥$1500 | 92 (46.0) | 108 (54.0) | 200 (66.4) |
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Country of birth (Australia), n (%) | 132 (48.4) | 141 (51.6) | 273 (90.7) | .45 | |
Age (years), mean (SD) | 41.9 (10.1) | 42.0 (10.3) | 41.9 (10.2) | .91 | |
Height (m), mean (SD) | 1.7 (0.1) | 1.7 (0.1) | 1.7 (0.1) | .53 | |
Weight (kg), mean (SD) | 94.4 (15.5) | 93.4 (13.9) | 93.9 (14.7) | .53 | |
Body mass index (kg/m2), mean (SD) | 32.2 (3.7) | 32.2 (4.1) | 32.2 (3.9) | .95 | |
Waist circumference at umbilicus (cm), mean (SD) | 106.8 (10.2) | 106.7 (11.5) | 106.7 (10.9) | .98 | |
Waist circumference at narrowest point (cm), mean (SD) | 98.3 (11.6) | 97.8 (11.2) | 98.1 (11.0) | .70 | |
Waist-to-height ratio at umbilicus, mean (SD) | 0.6 (0.1) | 0.6 (0.1) | 0.6 (0.1) | .76 | |
Waist-to-height ratio at narrowest point, mean (SD) | 0.58 (0.06) | 0.58 (0.06) | 0.58 (0.06) | .94 | |
Systolic blood pressure (mmHg), mean (SD) | 121 (13) | 121 (12) | 121 (12) | .97 | |
Diastolic blood pressure (mmHg), mean (SD) | 79 (10) | 79 (10) | 79 (10) | .88 | |
Resting heart rate (bpm), mean (SD) | 69 (11) | 68 (10) | 68 (10) | .56 | |
Total serum cholesterol (mmol/L), mean (SD) | 5.1 (0.9) | 5.1 (1.0) | 5.1 (1.0) | .54 | |
LDL cholesterol (mmol/L), mean (SD) | 3.1 (0.8) | 3.0 (0.9) | 3.1 (0.8) | .26 | |
HDL cholesterol (mmol/L), mean (SD) | 1.3 (0.3) | 1.3 (0.3) | 1.3 (0.3) | .78 | |
Triglycerides (mmol/L), mean (SD) | 1.6 (0.8) | 1.8 (1.1) | 1.7 (1.0) | .09 | |
LDL to HDL ratio, mean (SD) | 2.53 (0.79) | 2.39 (0.77) | 2.46 (0.78) | .14 | |
Glucose (mmol/L), mean (SD) | 4.7 (0.7) | 4.7 (0.6) | 4.7 (0.7) | .35 | |
Insulin (mIU/L), mean (SD) | 11.1 (11.7) | 10.5 (11.3) | 10.8 (11.4) | .67 | |
Physical functioning (SF36), mean (SD) | 85.9 (13.5) | 83.9 (18.4) | 84.9 (16.3) | .30 | |
Mental health (SF36), mean (SD) | 73.5 (16.1) | 73.2 (17.4) | 73.4 (16.8) | .89 | |
Total physical activity MET (min/week), mean (SD) | 3028 (3188) | 2877 (3100) | 2948 (3137) | .69 | |
Cognitive restraint scale, mean (SD) | 13.3 (3.0) | 13.4 (2.9) | 13.3 (3.0) | .70 | |
Uncontrolled eating scale, mean (SD) | 21.1 (4.8) | 20.9 (5.3) | 21.0 (5.0) | .63 | |
Emotional eating score, mean (SD) | 7.7 (2.3) | 7.7 (2.6) | 7.7 (2.5) | .93 | |
Total energy intake, mean (SD) | 9983 (3278) | 9972 (3236) | 9977 (3251) | .98 |
a
Mean change in a range of variables from baseline to 12 weeks and baseline to 24 weeks within each treatment group and the least squares mean (LSM) difference in change between treatment groups (ITT population LOCF approach).
Characteristic and follow-up time | Treatment group |
Absolute difference between groups |
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Basic | Enhanced | Enhanced vs basic | Difference at follow-up | Difference between groups | |
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12 weeks | –2.7 (4.0) | –3.3 (4.5) | 0.6 (–0.3, 1.6) | .21 | .21 |
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24 weeks | –3.3 (4.7) | –4.0 (6.2) | 0.7 (–0.6, 2.0) | .27 | |
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12 weeks | –2.90 (4.09) | –3.61 (4.69) | 0.71 (–0.30, 1.71) | .17 | .21 |
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24 weeks | –3.56 (4.94) | –4.28 (6.38) | 0.71 (–0.59, 2.02) | .28 | |
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12 weeks | 24.5 (43.1) | 32.9 (47.1) | 8.4 (–1.9, 18.7) | .11 | .13 |
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24 weeks | 31.5 (46.6) | 38.0 (48.7) | 6.5 (–4.3, 17.4) | .23 | |
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12 weeks | –3.40 (10.31) | –3.94 (9.66) | 0.52 (–1.60, 2.65) | .63 | .93 |
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24 weeks | –3.00 (10.11) | –2.33 (11.20) | 0.70 (–1.46, 2.86) | .53 | |
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12 weeks | –1.82 (8.50) | –2.30 (7.57) | 0.54 (–1.14, 2.22) | .53 | .78 |
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24 weeks | –1.18 (8.97) | –1.03 (8.05) | 0.09 (–1.68, 1.86) | .92 | |
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12 weeks | –0.9 (1.3) | –1.1 (1.5) | 0.2 (–0.1, 0.5) | .28 | .27 |
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24 weeks | –1.1 (1.5) | –1.3 (2.0) | 0.2 (–0.2, 0.6) | .29 | |
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12 weeks | –1.33 (7.12) | –2.35 (6.49) | 1.20 (–0.23, 2.64) | .10 | .05 |
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24 weeks | –1.62 (7.69) | –3.03 (7.22) | 1.59 (–0.02, 3.19) | .05 | |
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12 weeks | –3.4 (4.5) | –3.6 (5.3) | 0.2 (–0.9, 1.3) | .73 | .38 |
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24 weeks | –4.4 (5.3) | –5.3 (6.7) | 0.9 (–0.5, 2.3) | .22 | |
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12 weeks | –2.5 (4.3) | –3.4 (4.8) | 0.9 (–0.1, 1.9) | .09 | .10 |
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24 weeks | –3.1 (4.6) | –4.0 (6.2) | 0.9 (–0.3, 2.2) | .15 | |
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12 weeks | –0.02 (0.03) | –0.02 (0.03) | 0.00 (–0.01, 0.01) | .86 | .49 |
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24 weeks | –0.03 (0.03) | –0.03 (0.04) | 0.00 (–0.00, 0.01) | .28 | |
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12 weeks | –0.01 (0.02) | –0.02 (0.03) | 0.00 (–0.00, 0.01) | .11 | .14 |
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24 weeks | –0.02 (0.03) | –0.02 (0.04) | 0.00 (–0.00, 0.01) | .21 | |
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12 weeks | –0.08 (0.50) | –0.19 (0.58) | 0.12 (–0.00, 0.24) | .06 | .06 |
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24 weeks | 0.01 (0.52) | –0.08 (0.62) | 0.09 (–0.03, 0.22) | .15 | |
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12 weeks | –0.00 (0.45) | –0.07 (0.46) | 0.09 (–0.02, 0.19) | .11 | .13 |
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24 weeks | 0.04 (0.49) | –0.01 (0.50) | 0.07 (–0.05, 0.18) | .27 | |
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12 weeks | –0.00 (0.14) | –0.01 (0.16) | 0.00 (–0.03, 0.04) | .93 | .92 |
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24 weeks | 0.02 (0.13) | 0.02 (0.17) | 0.00 (–0.03, 0.04) | .80 | |
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12 weeks | –0.16 (0.63) | –0.26 (0.66) | 0.05 (–0.08, 0.18) | .48 | .30 |
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24 weeks | –0.09 (0.64) | –0.23 (0.66) | 0.09 (–0.04, 0.23) | .18 | |
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12 weeks | 0.00 (0.40) | –0.04 (0.35) | 0.06 (–0.03, 0.15) | .21 | .21 |
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24 weeks | –0.01 (0.42) | –0.04 (0.37) | 0.04 (–0.05, 0.14) | .35 | |
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12 weeks | –0.22 (0.55) | –0.22 (0.55) | 0.02 (–0.10, 0.14) | .78 | .37 |
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24 weeks | –0.07 (0.46) | –0.12 (0.54) | 0.08 (–0.03, 0.18) | .17 | |
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12 weeks | –1.76 (10.91) | –1.80 (5.47) | 0.29 (–1.25, 1.82) | .71 | .81 |
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24 weeks | –2.51 (10.36) | –2.31 (6.18) | 0.04 (–1.47, 1.55) | .96 | |
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12 weeks | 2.48 (20.05) | 4.71 (15.74) | 1.14 (–2.34, 4.62) | .52 | .63 |
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24 weeks | 3.58 (10.89) | 4.62 (15.03) | 0.17 (–2.30, 2.64) | .89 | |
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12 weeks | 2.13 (15.06) | 4.04 (13.43) | 1.58 (–1.41, 4.57) | .30 | .31 |
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24 weeks | 1.77 (14.83) | 3.82 (23.80) | 1.68 (–2.69, 6.04) | .45 | |
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12 weeks | 215.29 (2448.3) | 373.56 (2467.1) | 96.19 (–424.3, 616.66) | .72 | .36 |
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24 weeks | 203.58 (2668.5) | 619.84 (3156.7) | 358.58 (–285.1, 1002.3) | .27 | |
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12 weeks | 319.92 (2481.3) | 1059.8 (3094.2) | 675.22 (–11.32, 1361.8) | .05 | .06 |
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24 weeks | 94.15 (2303.2) | 706.99 (3173.9) | 548.38 (–142.9, 1239.6) | .12 | |
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12 weeks | 1.32 (2.72) | 1.74 (3.28) | 0.48 (–0.15, 1.11) | .14 | .08 |
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24 weeks | 1.36 (2.96) | 1.90 (3.37) | 0.59 (–0.09, 1.27) | .09 | |
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12 weeks | –1.71 (3.44) | –1.78 (3.41) | 0.14 (–0.58, 0.86) | .70 | .65 |
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24 weeks | –1.67 (3.59) | –1.76 (3.62) | 0.17 (–0.59, 0.93) | .66 | |
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12 weeks | –0.37 (1.38) | –0.48 (1.56) | 0.10 (–0.22, 0.41) | .54 | .43 |
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24 weeks | –0.45 (1.68) | –0.61 (1.72) | 0.15 (–0.21, 0.51) | .41 | |
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12 weeks | –985.5 (2386.7) | –1248 (2458.1) | 267.74 (–186.4, 721.90) | .25 | .57 |
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24 weeks | –952.4 (2293.8) | –929.7 (2363.6) | 18.23 (–439.2, 475.66) | .94 |
Mean change in a range of variables from baseline to 12 weeks and baseline to 24 weeks within each treatment group and the least squares mean (LSM) difference in change between treatment groups (ITT population BOCF approach).
Characteristic and follow-up time | Treatment group |
Absolute difference between groups |
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Basic | Enhanced | Enhanced vs basic | Difference at follow-up | Difference between groups | |
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12 weeks | –2.7 (4.0) | –3.3 (4.5) | 0.6 (–0.3, 1.6) | .21 | .13 |
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24 weeks | –3.0 (4.5) | –3.9 (6.2) | 1.0 (–0.2, 2.2) | .11 | |
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12 weeks | –2.90 (4.09) | –3.61 (4.69) | 0.71 (–0.30, 1.71) | .17 | .12 |
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24 weeks | –3.17 (4.74) | –4.19 (6.34) | 1.02 (–0.27, 2.30) | .12 | |
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12 weeks | 24.5 (43.1) | 32.9 (47.1) | 8.43 (–1.87, 18.73) | .11 | .09 |
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24 weeks | 28.7 (45.4) | 36.7 (48.4) | 8.07 (–2.58, 18.73) | .13 | |
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12 weeks | –3.40 (10.31) | –3.94 (9.66) | 0.52 (–1.60, 2.65) | .63 | .92 |
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24 weeks | –2.46 (9.71) | –2.14 (10.85) | 0.35 (–1.77, 2.47) | .75 | |
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12 weeks | –1.82 (8.50) | –2.30 (7.57) | 0.54 (–1.14, 2.22) | .53 | .68 |
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24 weeks | –0.89 (8.59) | –0.91 (7.60) | 0.08 (–1.62, 1.78) | .93 | |
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12 weeks | –0.93 (1.31) | –1.11 (1.52) | 0.18 (–0.14, 0.50) | .28 | .20 |
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24 weeks | –0.97 (1.45) | –1.24 (2.00) | 0.28 (–0.12, 0.68) | .17 | |
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12 weeks | –1.33 (7.12) | –2.35 (6.49) | 1.20 (–0.23, 2.64) | .10 | .03 |
|
24 weeks | –1.30 (7.15) | –2.78 (6.86) | 1.64 (0.12, 3.15) | .03 | |
|
|
|
|
|
|
|
|
12 weeks | –3.37 (4.52) | –3.57 (5.31) | 0.20 (–0.93, 1.33) | .73 | .26 |
|
24 weeks | –3.81 (5.17) | –4.93 (6.73) | 1.12 (–0.25, 2.48) | .11 | |
|
|
|
|
|
|
|
|
12 weeks | –2.48 (4.27) | –3.37 (4.80) | 0.90 (–0.13, 1.92) | .09 | .06 |
|
24 weeks | –2.73 (4.26) | –3.79 (6.19) | 1.08 (–0.13, 2.29) | .08 | |
|
|
|
|
|
|
|
|
12 weeks | –0.02 (0.03) | –0.02 (0.03) | 0.00 (–0.01, 0.01) | .86 | .35 |
|
24 weeks | –0.02 (0.03) | –0.03 (0.04) | 0.01 (–0.00, 0.01) | .15 | |
|
|
|
|
|
|
|
|
12 weeks | –0.01 (0.02) | –0.02 (0.03) | 0.00 (–0.00, 0.01) | .11 | .09 |
|
24 weeks | –0.02 (0.02) | –0.02 (0.04) | 0.01 (–0.00, 0.01) | .12 | |
|
|
|
|
|
|
|
|
12 weeks | –0.08 (0.50) | –0.19 (0.58) | 0.12 (–0.00, 0.24) | .06 | .06 |
|
24 weeks | 0.01 (0.44) | –0.06 (0.58) | 0.08 (–0.04, 0.19) | .20 | |
|
|
|
|
|
|
|
|
12 weeks | –0.00 (0.45) | –0.07 (0.46) | 0.09 (–0.02, 0.19) | .11 | .10 |
|
24 weeks | 0.02 (0.39) | –0.02 (0.46) | 0.06 (–0.04, 0.16) | .27 | |
|
|
|
|
|
|
|
|
12 weeks | –0.00 (0.14) | –0.01 (0.16) | 0.00 (–0.03, 0.04) | .93 | .86 |
|
24 weeks | 0.02 (0.10) | 0.02 (0.16) | 0.01 (–0.02, 0.04) | .68 | |
|
|
|
|
|
|
|
|
12 weeks | –0.16 (0.63) | –0.26 (0.66) | 0.05 (–0.08, 0.18) | .48 | .27 |
|
24 weeks | –0.08 (0.43) | –0.21 (0.65) | 0.08 (–0.04, 0.19) | .18 | |
|
|
|
|
|
|
|
|
12 weeks | 0.00 (0.40) | –0.04 (0.35) | 0.06 (–0.03, 0.15) | .21 | .23 |
|
24 weeks | –0.02 (0.34) | –0.04 (0.36) | 0.03 (–0.06, 0.11) | .51 | |
|
|
|
|
|
|
|
|
12 weeks | –0.22 (0.55) | –0.22 (0.55) | 0.02 (–0.10, 0.14) | .78 | .22 |
|
24 weeks | –0.02 (0.38) | –0.10 (0.50) | 0.10 (0.00, 0.20) | .05 | |
|
|
|
|
|
|
|
|
12 weeks | –1.76 (10.91) | –1.80 (5.47) | 0.29 (–1.25, 1.82) | .71 | .82 |
|
24 weeks | –2.37 (9.85) | –2.16 (5.92) | 0.02 (–1.43, 1.47) | .98 | |
|
|
|
|
|
|
|
|
12 weeks | 2.48 (20.05) | 4.71 (15.74) | 1.14 (–2.34, 4.62) | .52 | .90 |
|
24 weeks | 3.48 (10.40) | 3.38 (13.63) | 0.81 (–1.58, 3.21) | .50 | |
|
|
|
|
|
|
|
|
12 weeks | 2.13 (15.06) | 4.04 (13.43) | 1.58 (–1.41, 4.57) | .30 | .22 |
|
24 weeks | 0.82 (11.74) | 3.15 (23.39) | 2.03 (–2.11, 6.17) | .34 | |
|
|
|
|
|
|
|
|
12 weeks | 215.29 (2448.3) | 373.56 (2467.1) | 96.19 (–424.3, 616.66) | .72 | .20 |
|
24 weeks | 136.47 (2303.8) | 653.82 (2882.0) | 474.17 (–112.4, 1060.7) | .11 | |
|
|
|
|
|
|
|
|
12 weeks | 319.92 (2481.3) | 1059.8 (3094.2) | 675.22 (–11.32, 1361.8) | .05 | .05 |
|
24 weeks | 36.69 (1838.9) | 485.19 (2766.5) | 405.53 (–191.5, 1002.6) | .18 | |
|
|
|
|
|
|
|
|
12 weeks | 1.32 (2.72) | 1.74 (3.28) | 0.48 (–0.15, 1.11) | .14 | .12 |
|
24 weeks | 1.32 (2.75) | 1.71 (3.10) | 0.43 (–0.22, 1.08) | .19 | |
|
|
|
|
|
|
|
|
12 weeks | –1.71 (3.44) | –1.78 (3.41) | 0.14 (–0.58, 0.86) | .70 | .73 |
|
24 weeks | –1.55 (3.37) | –1.56 (3.48) | 0.09 (–0.65, 0.82) | .82 | |
|
|
|
|
|
|
|
|
12 weeks | –0.37 (1.38) | –0.48 (1.56) | 0.10 (–0.22, 0.41) | .54 | .38 |
|
24 weeks | –0.40 (1.59) | –0.57 (1.68) | 0.17 (–0.19, 0.52) | .36 | |
|
|
|
|
|
|
|
|
12 weeks | –985.5 (2386.7) | –1248 (2458.1) | 267.74 (–186.4, 721.90) | .25 | .54 |
|
24 weeks | –787.1 (2095.4) | –761.4 (2046.2) | 22.36 (–407.4, 452.10) | .92 |
Mean change in a range of variables from baseline to 12 weeks and baseline to 24 weeks within each treatment group and the least squares mean (LSM) difference in change between treatment groups (completers population).
Characteristic and follow-up time | Treatment group |
Absolute difference between groups |
|
|||
|
Basic | Enhanced | Enhanced vs basic | Difference at follow-up | Difference between groups | |
|
|
|
|
|
|
|
|
12 weeks | –3.7 (4.0) | –4.3 (4.6) | 0.6 (–0.6, 1.8) | .34 | .35 |
|
24 weeks | –4.1 (4.7) | –4.8 (6.6) | 0.7 (–0.8, 2.3) | .35 | |
|
|
|
|
|
|
|
|
12 weeks | –3.89 (4.10) | –4.59 (4.81) | 0.69 (–0.54, 1.92) | .27 | .27 |
|
24 weeks | –4.48 (4.91) | –5.18 (6.70) | 0.71 (–0.88, 2.31) | .38 | |
|
|
|
|
|
|
|
|
12 weeks | 33.7 (47.5) | 41.3 (49.4) | 7.65 (–5.65, 20.94) | .26 | .31 |
|
24 weeks | 41.2 (49.5) | 45.7 (50.0) | 4.76 (–8.40, 17.92) | .48 | |
|
|
|
|
|
|
|
|
12 weeks | –4.91 (12.38) | –4.91 (10.63) | 0.37 (–2.48, 3.21) | .80 | .65 |
|
24 weeks | –3.98 (12.11) | –2.95 (12.65) | 0.78 (–2.15, 3.71) | .60 | |
|
|
|
|
|
|
|
|
12 weeks | –2.87 (10.33) | –2.86 (8.37) | 0.43 (–1.72, 2.59) | .69 | .91 |
|
24 weeks | –1.43 (10.89) | –1.25 (8.90) | 0.22 (–2.14, 2.58) | .85 | |
|
|
|
|
|
|
|
|
12 weeks | –1.27 (1.33) | –1.42 (1.57) | 0.15 (–0.26, 0.55) | .48 | .48 |
|
24 weeks | –1.53 (1.57) | –1.70 (2.17) | 0.16 (–0.37, 0.70) | .55 | |
|
|
|
|
|
|
|
|
12 weeks | –1.90 (8.31) | –3.07 (7.18) | 1.37 (–0.48, 3.21) | .15 | .05 |
|
24 weeks | –2.09 (8.97) | –3.81 (7.78) | 1.76 (–0.34, 3.87) | .10 | |
|
|
|
|
|
|
|
|
12 weeks | –4.44 (4.56) | –4.51 (5.50) | 0.02 (–1.38, 1.42) | .98 | .64 |
|
24 weeks | –6.13 (5.36) | –6.83 (7.06) | 0.56 (–1.16, 2.29) | .52 | |
|
|
|
|
|
|
|
|
12 weeks | –3.18 (4.54) | –4.28 (5.01) | 1.05 (–0.24, 2.34) | .11 | .15 |
|
24 weeks | –4.39 (4.68) | –5.25 (6.75) | 0.82 (–0.81, 2.44) | .32 | |
|
|
|
|
|
|
|
|
12 weeks | –0.03 (0.03) | –0.03 (0.03) | 0.00 (–0.01, 0.01) | .91 | .75 |
|
24 weeks | –0.04 (0.03) | –0.04 (0.04) | 0.00 (–0.01, 0.01) | .65 | |
|
|
|
|
|
|
|
|
12 weeks | –0.02 (0.03) | –0.02 (0.03) | 0.01 (–0.00, 0.01) | .14 | .19 |
|
24 weeks | –0.03 (0.03) | –0.03 (0.04) | 0.00 (–0.01, 0.01) | .42 | |
|
|
|
|
|
|
|
|
12 weeks | –0.12 (0.54) | –0.23 (0.65) | 0.12 (–0.04, 0.28) | .14 | .09 |
|
24 weeks | 0.02 (0.57) | –0.09 (0.70) | 0.12 (–0.06, 0.30) | .20 | |
|
|
|
|
|
|
|
|
12 weeks | –0.02 (0.45) | –0.08 (0.53) | 0.08 (–0.06, 0.22) | .27 | .26 |
|
24 weeks | 0.04 (0.52) | –0.02 (0.57) | 0.09 (–0.07, 0.26) | .27 | |
|
|
|
|
|
|
|
|
12 weeks | –0.01 (0.14) | –0.01 (0.18) | 0.01 (–0.04, 0.05) | .76 | .71 |
|
24 weeks | 0.03 (0.13) | 0.04 (0.19) | 0.00 (–0.04, 0.05) | .86 | |
|
|
|
|
|
|
|
|
12 weeks | –0.21 (0.64) | –0.34 (0.73) | 0.06 (–0.10, 0.22) | .47 | .21 |
|
24 weeks | –0.14 (0.56) | –0.30 (0.77) | 0.07 (–0.09, 0.24) | .38 | |
|
|
|
|
|
|
|
|
12 weeks | –0.02 (0.44) | –0.05 (0.40) | 0.05 (–0.07, 0.18) | .38 | .43 |
|
24 weeks | –0.04 (0.46) | –0.07 (0.44) | 0.04 (–0.10, 0.17) | .61 | |
|
|
|
|
|
|
|
|
12 weeks | –0.31 (0.64) | –0.27 (0.61) | 0.00 (–0.16, 0.16) | .99 | .35 |
|
24 weeks | –0.03 (0.50) | –0.15 (0.61) | 0.15 (–0.00, 0.29) | .05 | |
|
|
|
|
|
|
|
|
12 weeks | –2.69 (13.26) | –2.25 (6.14) | 0.48 (–1.13, 2.08) | .56 | .61 |
|
24 weeks | –4.03 (12.62) | –3.15 (6.95) | 0.20 (–1.34, 1.73) | .80 | |
|
|
|
|
|
|
|
|
12 weeks | 3.54 (24.91) | 5.21 (16.40) | 0.57 (–3.93, 5.08) | .80 | .88 |
|
24 weeks | 5.57 (12.74) | 4.78 (15.93) | 1.25 (–1.89, 4.40) | .43 | |
|
|
|
|
|
|
|
|
12 weeks | 2.36 (18.09) | 4.88 (14.97) | 1.39 (–2.51, 5.28) | .48 | .53 |
|
24 weeks | 1.31 (14.87) | 4.38 (27.63) | 1.87 (–4.18, 7.93) | .54 | |
|
|
|
|
|
|
|
|
12 weeks | 164.57 (2799.8) | 432.99 (2735.8) | 214.87 (–403.0, 832.76) | .49 | .28 |
|
24 weeks | 230.41 (2997.8) | 932.18 (3408.2) | 491.04 (–381.0, 1363.0) | .27 | |
|
|
|
|
|
|
|
|
12 weeks | 418.22 (3102.2) | 1598.7 (3600.4) | 1139.3 (118.76, 2159.9) | .03 | .06 |
|
24 weeks | 91.73 (2926.8) | 808.65 (3543.6) | 587.05 (–604.7, 1778.8) | .33 | |
|
|
|
|
|
|
|
|
12 weeks | 2.11 (2.94) | 2.29 (3.48) | 0.01 (–0.78, 0.79) | .98 | .66 |
|
24 weeks | 2.13 (3.24) | 2.44 (3.46) | 0.19 (–0.69, 1.07) | .66 | |
|
|
|
|
|
|
|
|
12 weeks | –2.60 (3.82) | –2.26 (3.76) | 0.12 (–0.81, 1.05) | .81 | .96 |
|
24 weeks | –2.46 (3.98) | –2.20 (3.96) | 0.07 (–0.92, 1.07) | .89 | |
|
|
|
|
|
|
|
|
12 weeks | –0.53 (1.61) | –0.59 (1.75) | 0.06 (–0.37, 0.48) | .79 | .58 |
|
24 weeks | –0.63 (1.98) | –0.79 (1.94) | 0.14 (–0.36, 0.64) | .58 | |
|
|
|
|
|
|
|
|
12 weeks | –1480 (2695.4) | –1467 (2428.2) | 90.91 (–462.8, 644.63) | .75 | .82 |
|
24 weeks | –1285 (2559.6) | –1047 (2338.7) | 208.94 (–379.6, 797.48) | .48 |
Mean change in total website usage for the completers population and the ITT with LOCF from baseline to 12 weeks and baseline to 24 weeks within each treatment group.
Characteristic and follow-up time | Treatment group |
Absolute difference between groups |
|
||||
|
Basic | Enhanced | Enhanced vs basic | Difference at follow-up | Difference between groups | ||
|
|
|
|
||||
|
|
|
|
||||
|
|
12 weeks | 24.6 (25.5) | 34.1 (28.1) | 9.45 (3.34, 15.56) | .002 | .002 |
|
|
24 weeks | 31.8 (33.9) | 43.1 (34.0) | 12.47 (4.73, 20.20) | .002 | |
|
|
|
|
|
|
||
|
|
|
|
||||
|
|
12 weeks | 29.7 (26.6) | 38.7 (28.5) | 9.2 (–1.9, 16.5) | .01 | .02 |
|
|
24 weeks | 42.0 (36.1) | 49.8 (33.3) | 8.1 (–3.3, 19.4) | .16 |
The aim of the study was to evaluate whether overweight and obese adults randomized to a commercial Web-based weight-loss program providing greater social support and more personalized feedback achieved a greater reduction in BMI and increased usage of program features compared to those randomized to a standard version of the program. We found no differences in weight loss or most of the secondary health outcomes between the basic and enhanced features versions of the Web-based weight-loss program after 24 weeks, despite previous reports that provision of enhanced features within Web-based formats does enhance weight-loss outcomes [
In the current study, the basic and enhanced versions may have produced similar weight loss because several of these components were similar (self-monitoring, social support, structured program) or absent (eg, counselor feedback) in both versions. Khaylis et al [
In the completers population of the current study, significant correlations were found between total website usage and the percentage weight loss at 12 and 24 weeks. Participants who achieved clinically important weight loss (≥5%) at either time point used the website almost 4 times more than those who were not successful (<5% weight loss). Further, the website log-ins among those deemed successful was substantially greater than the number of log-ins reported for the enhanced group. Those with successful weight loss logged in 2 to 3 times per week, compared to just once or twice a week for those randomized to the enhanced group and less than once a week for those randomized to the basic group.
The correlation between number of log-ins and weight loss was moderate across all study participants and there was also no between-group difference. This suggests that although being allocated to the enhanced program did facilitate more frequent website log-ins, provision of additional features is not enough to facilitate greater engagement and weight loss. Further research examining which combination of website features optimize program use and reduce attrition are needed. Based on the current study, future modifications to the enhanced program would need to achieve a 50% increase in the number of participant log-ins than that in the current study. This would mean getting participants to use the program at least 2 to 3 times per week as a strategy to facilitate clinically important ≥5% weight loss. Establishing and testing these targets could ease the burden and fatigue associated with program usage targets that are not achievable or sustainable. Although between-groups differences might typically be explained by confounders such as energy intake and physical activity, these were not different between groups. It is more likely that differential use of social support features, including blogs, forums, and chat rooms, explain the between-group difference and this requires further research. We cannot tell whether the reminders schedule to log in and use of program features in the current study was the key driver of this and this also needs to be examined in future studies.
A limitation of the current study is that it did not have a waitlist control group at 6 months. However, this was not required to answer the research question. Attrition reduced the power to detect significant differences between groups, particularly for the secondary outcomes; however, there were a few trends suggesting that better retention would not have changed the outcomes in any substantial way. The strengths of this study include the use of an RCT, large sample size, use of blinded assessors, and the comparison of the effectiveness of the 2 versions of the weight-loss programs up to 24 weeks. Further, few commercial Web-based programs have been subjected to evaluation by RCT, with none previously conducted in Australia. Importantly, this study has demonstrated the efficacy of a commercial Web-based weight-loss program in achieving clinically important weight loss.
In conclusion, commercial Web-based weight-loss programs can be effective at achieving clinically meaningful weight loss up to 24 weeks. Although adding enhanced features that provide additional feedback, reminders, and social support promotes greater retention and engagement, it does not necessarily increase weight loss substantially. Further research into Web-based features that optimize website usage, program engagement, and weight-loss success is warranted.
CONSORT-eHEALTH checklist V1.6.2 [
Sample weekly report_5.
Sample weekly report_5a.
Australian Eating Survey
analysis of variance
Australian New Zealand Clinical Trials Registry
body mass index
baseline observation carried forward
Consolidated Standards of Reporting Trials
food-frequency questionnaire
generalized linear mixed model
high-density lipoprotein
International Physical Activity Questionnaire-short form
intention-to-treat
low-density lipoprotein
last observation carried forward
least squares mean
total metabolic equivalent
randomized controlled trial
short message service
Three-Factor Eating Questionnaire-R18
We would like to thank the study participants for participating in the trial; research assistants (Rebecca Collins, Trevor Cripps, James Dower, Sharenjit Gill, Jenna Hannan, Skye Huxley, Hannah Mackay, Bryana Melnick, Justin Nicol, Hannah Lucas, Tom Mitchell, Huiru Teoh, Janine Wright, and Mei Yap) who helped with data collection; Louana Moller, Lynn Clarke, and Narelle Eddington from Hunter Area Pathology Service; Scott Penn, Anna Crook, Julian Barton, Sandra Mitchell, and Laura Welsford from SP Health Pty Ltd; Patrick McElduff (PhD) and Daniel Barker for conducting the statistical analyses; and Dr. Megan Jensen (PhD) who assisted with manuscript preparation. This trial was funded by an Australian Research Council Linkage Project grant (2009-2012) (LP0990414, G0189752), with SP Health as the Industry Partner Organization (G0189753). CEC is supported by a National Health and Medical Research Council Australian Career Development Fellowship (#6315005). MN is supported by a postdoctoral fellowship from the Priority Research Centre in Physical Activity and Nutrition, The University of Newcastle.
CEC has been a nutrition consultant to SP Health Co M Hutchesson (nee Neve) was funded by a Penn Health postdoctoral fellowship. All other authors declare that they have no competing interests.