Adult Weight Management

AWM: New Technology and Telenutrition (2013)

Citation:

Krukowski RA, Harvey-Berino J, Ashikaga T, Thomas CS, Micco N. Internet-based weight control: The relationship between web features and weight loss. Telemed J E Health. 2008; 14(8): 775-782.

PubMed ID: 18954247
 
Study Design:
Non-Controlled Trial
Class:
D - Click here for explanation of classification scheme.
Quality Rating:
Positive POSITIVE: See Quality Criteria Checklist below.
Research Purpose:

To examine the utilization patterns of a weight control website and the relationship of the web features to weight loss and maintenance.

Inclusion Criteria:
  • 18 years of age or older
  • Body mass index more than 25 and 39.9kg/m2 or less
  • Access to a computer with at least 64 MB RAM, a sound card, 350 MHz processor and a 33-kilobits-per-second connection speed and an adequate Internet connection
  • Provided informed consent
  • Agreed to not participate in other weight-loss treatment programs during the course of the study.
Exclusion Criteria:
  • Planning to move from the area within the next year
  • Smoking
  • Taking medications associated with weight change
  • Planning a pregnancy in the next year
  • Conflicts with scheduled meeting times.
Description of Study Protocol:

Recruitment

Recruited from 2003 to 2005 through newspaper advertisements.

Design

Non-controlled trial.

Blinding Used

Implied with measurements.

Intervention

  • Participants received standard behavioral weight-loss treatment over 12 months, which focused on changing dietary and physical activity patterns through behavior modification strategies
  • Lesson topics included stimulus control, problem solving, goal setting, social support and relapse prevention
  • Weekly group web chat sessions were offered during the treatment period from months zero to six with monthly maintenance meeting held from months seven to 12
  • The maintenance period targets maintaining skills learned during treatment with less program structure to allow the participants more independence in managing their lifestyle behaviors
  • A registered dietitian or a master's level graduate student both trained in behavior therapy principles and the VTrim curriculum, facilitated web chats and in-person meetings
  • Participants reviewed each week's lesson and submitted electronically, the corresponding homework assignment to their facilitator before the meeting
  • Participants were prescribed calorie goals of between 1,200 to 2,100 calories based on baseline body weights. Calorie goals were determined by multiplying body weight by 12 to estimate current daily intake needs and then subtracting 1,000 calories to produce a loss of one to two pounds per week. 

Statistical Analysis

  • The analyses focused on web use during treatment (zero to six months) and maintenance (seven to 12 months) for subjects with complete weight data at baseline, six and 12 months
  • Outliers were examined and one participant was removed from the analyses as an outlier
  • Exploratory factor analysis with a varimax rotation was used to examine the clustering of the feature use with Scree plots, and factor loadings were examined to determine the number of factors for the treatment and maintenance periods
  • Data were analyzed using SAS version 9.1 using a 5% significance level for formal testing
  • All procedures were reviewed and approved by the University of Vermont Institutional Review Board for the Social Sciences.
Data Collection Summary:

Timing of Measurements

Measurements made at baseline, six and 12 months.

Dependent Variables

  • Weight loss: Weight was measured on a beam-balance scale at baseline, six months and 12 months with participants in street clothes without shoes
  • Website usage (number of log-ins and utilization of various web features) was automatically tracked throughout the study
  • Dietary intake, physical activity levels, computer ability and attitudes, and measures of social influence were also assessed and have been reported elsewhere.

Independent Variables

  • Participants received standard behavioral weight-loss treatment over 12 months, which focused on changing dietary and physical activity patterns through behavior modification strategies
  • Lesson topics included stimulus control, problem solving, goal setting, social support and relapse prevention
  • Weekly group web chat sessions were offered during the treatment period from months zero to six with monthly maintenance meeting held from months seven to 12
  • The maintenance period targets maintaining skills learned during treatment with less program structure to allow the participants more independence in managing their lifestyle behaviors
  • A registered dietitian or a master's level graduate student both trained in behavior therapy principles and the VTrim curriculum, facilitated web chats and in-person meetings
  • Participants reviewed each week's lesson and submitted electronically, the corresponding homework assignment to their facilitator before the meeting.
  • Participants were prescribed calorie goals of between 1,200 to 2,100 calories based on baseline body weights. Calorie goals were determined by multiplying body weight by 12 to estimate current daily intake needs and then subtracting 1,000 calories to produce a loss of one to two pounds per week.
Description of Actual Data Sample:
  • Initial N: 123 (102 women, 21 men) recruited
  • Attrition (final N): Treatment attrition was 21%; 63% of participants provided data at all assessment points (baseline, six and 12 months).
  • Age: Mean age of 46.8 years
  • Ethnicity: White
  • Other relevant demographics: Well educated (74% had college degrees)
  • Anthropometrics: Average BMI of 31.7kg/m2
  • Location: Vermont.
Summary of Results:

Key Findings

  • Participants lost on average of 7.5kg±6.4kg or 8.5% of baseline weight at six months and 6.6kg±6.6kg or 7.5% of baseline weight at 12 months
  • The only significant baseline difference between non-completers and completers was weight, such that non-completers were significantly heavier than completers at baseline (93.8kg±21.9kg vs. 89.7kg±12.3kg); P=0.003
  • Participants logged on to the website on average 190.9±138.5 times during treatment and 94.6±96.1 times during the maintenance
  • Simple linear regression modeling indicated that utilization of the features under Factor 1 (motivation/support) (R2=0.05, P<0.05) and Factor 2 (feedback)(R2=0.07, P<0.01)
  • Simple linear regression modeling of additional weight loss over the maintenance period indicated that utilization of the features in Factor F (social support) (R2=0.08, P=0.01) was the most highly related to weight change while none of the other sub-scales achieved statistical significance
  • When examining the clustering of web feature utilization and weight loss, the feedback factor (progress charts, physiological calculators, and past journals) was the best predictor of weight loss during the treatment period (baseline to six months), while the social support factor (web chats and biographical information with e-mail addresses of participants) was the best predictor during maintenance.
Author Conclusion:

Analysis of various components of the website indicated that consistent with previous research, web features that provided participants with visual representations of goal progress, self-monitoring feedback and social support were predictive of weight loss and maintenance, such that the factor including progress charts, physiological calculators and past journals was the best predictor of weight loss.

Funding Source:
Government: USDA Hatch Act Funds (VT-NS-00904), NIDDK (R01 DK056746)
Reviewer Comments:

Treatment attrition was 21%.

Quality Criteria Checklist: Primary Research
Relevance Questions
  1. Would implementing the studied intervention or procedure (if found successful) result in improved outcomes for the patients/clients/population group? (Not Applicable for some epidemiological studies) Yes
  1. Would implementing the studied intervention or procedure (if found successful) result in improved outcomes for the patients/clients/population group? (Not Applicable for some epidemiological studies) Yes
  2. Did the authors study an outcome (dependent variable) or topic that the patients/clients/population group would care about? Yes
  2. Did the authors study an outcome (dependent variable) or topic that the patients/clients/population group would care about? Yes
  3. Is the focus of the intervention or procedure (independent variable) or topic of study a common issue of concern to dieteticspractice? Yes
  3. Is the focus of the intervention or procedure (independent variable) or topic of study a common issue of concern to dieteticspractice? Yes
  4. Is the intervention or procedure feasible? (NA for some epidemiological studies) Yes
  4. Is the intervention or procedure feasible? (NA for some epidemiological studies) Yes
 
Validity Questions
  1. Was the research question clearly stated? Yes
1. Was the research question clearly stated? Yes
  1.1. Was (were) the specific intervention(s) or procedure(s) [independent variable(s)] identified? Yes
  1.1. Was (were) the specific intervention(s) or procedure(s) [independent variable(s)] identified? Yes
  1.2. Was (were) the outcome(s) [dependent variable(s)] clearly indicated? Yes
  1.2. Was (were) the outcome(s) [dependent variable(s)] clearly indicated? Yes
  1.3. Were the target population and setting specified? Yes
  1.3. Were the target population and setting specified? Yes
  2. Was the selection of study subjects/patients free from bias? Yes
2. Was the selection of study subjects/patients free from bias? Yes
  2.1. Were inclusion/exclusion criteria specified (e.g., risk, point in disease progression, diagnostic or prognosis criteria), and with sufficient detail and without omitting criteria critical to the study? Yes
  2.1. Were inclusion/exclusion criteria specified (e.g., risk, point in disease progression, diagnostic or prognosis criteria), and with sufficient detail and without omitting criteria critical to the study? Yes
  2.2. Were criteria applied equally to all study groups? Yes
  2.2. Were criteria applied equally to all study groups? Yes
  2.3. Were health, demographics, and other characteristics of subjects described? Yes
  2.3. Were health, demographics, and other characteristics of subjects described? Yes
  2.4. Were the subjects/patients a representative sample of the relevant population? Yes
  2.4. Were the subjects/patients a representative sample of the relevant population? Yes
  3. Were study groups comparable? N/A
3. Were study groups comparable? N/A
  3.1. Was the method of assigning subjects/patients to groups described and unbiased? (Method of randomization identified if RCT) N/A
  3.1. Was the method of assigning subjects/patients to groups described and unbiased? (Method of randomization identified if RCT) N/A
  3.2. Were distribution of disease status, prognostic factors, and other factors (e.g., demographics) similar across study groups at baseline? N/A
  3.2. Were distribution of disease status, prognostic factors, and other factors (e.g., demographics) similar across study groups at baseline? N/A
  3.3. Were concurrent controls or comparisons used? (Concurrent preferred over historical control or comparison groups.) N/A
  3.3. Were concurrent controls or comparisons used? (Concurrent preferred over historical control or comparison groups.) N/A
  3.4. If cohort study or cross-sectional study, were groups comparable on important confounding factors and/or were preexisting differences accounted for by using appropriate adjustments in statistical analysis? N/A
  3.4. If cohort study or cross-sectional study, were groups comparable on important confounding factors and/or were preexisting differences accounted for by using appropriate adjustments in statistical analysis? N/A
  3.5. If case control study, were potential confounding factors comparable for cases and controls? (If case series or trial with subjects serving as own control, this criterion is not applicable.) N/A
  3.5. If case control study, were potential confounding factors comparable for cases and controls? (If case series or trial with subjects serving as own control, this criterion is not applicable.) N/A
  3.6. If diagnostic test, was there an independent blind comparison with an appropriate reference standard (e.g., "gold standard")? N/A
  3.6. If diagnostic test, was there an independent blind comparison with an appropriate reference standard (e.g., "gold standard")? N/A
  4. Was method of handling withdrawals described? Yes
4. Was method of handling withdrawals described? Yes
  4.1. Were follow-up methods described and the same for all groups? Yes
  4.1. Were follow-up methods described and the same for all groups? Yes
  4.2. Was the number, characteristics of withdrawals (i.e., dropouts, lost to follow up, attrition rate) and/or response rate (cross-sectional studies) described for each group? (Follow up goal for a strong study is 80%.) Yes
  4.2. Was the number, characteristics of withdrawals (i.e., dropouts, lost to follow up, attrition rate) and/or response rate (cross-sectional studies) described for each group? (Follow up goal for a strong study is 80%.) Yes
  4.3. Were all enrolled subjects/patients (in the original sample) accounted for? Yes
  4.3. Were all enrolled subjects/patients (in the original sample) accounted for? Yes
  4.4. Were reasons for withdrawals similar across groups? Yes
  4.4. Were reasons for withdrawals similar across groups? Yes
  4.5. If diagnostic test, was decision to perform reference test not dependent on results of test under study? N/A
  4.5. If diagnostic test, was decision to perform reference test not dependent on results of test under study? N/A
  5. Was blinding used to prevent introduction of bias? Yes
5. Was blinding used to prevent introduction of bias? Yes
  5.1. In intervention study, were subjects, clinicians/practitioners, and investigators blinded to treatment group, as appropriate? N/A
  5.1. In intervention study, were subjects, clinicians/practitioners, and investigators blinded to treatment group, as appropriate? N/A
  5.2. Were data collectors blinded for outcomes assessment? (If outcome is measured using an objective test, such as a lab value, this criterion is assumed to be met.) Yes
  5.2. Were data collectors blinded for outcomes assessment? (If outcome is measured using an objective test, such as a lab value, this criterion is assumed to be met.) Yes
  5.3. In cohort study or cross-sectional study, were measurements of outcomes and risk factors blinded? N/A
  5.3. In cohort study or cross-sectional study, were measurements of outcomes and risk factors blinded? N/A
  5.4. In case control study, was case definition explicit and case ascertainment not influenced by exposure status? N/A
  5.4. In case control study, was case definition explicit and case ascertainment not influenced by exposure status? N/A
  5.5. In diagnostic study, were test results blinded to patient history and other test results? N/A
  5.5. In diagnostic study, were test results blinded to patient history and other test results? N/A
  6. Were intervention/therapeutic regimens/exposure factor or procedure and any comparison(s) described in detail? Were interveningfactors described? Yes
6. Were intervention/therapeutic regimens/exposure factor or procedure and any comparison(s) described in detail? Were interveningfactors described? Yes
  6.1. In RCT or other intervention trial, were protocols described for all regimens studied? Yes
  6.1. In RCT or other intervention trial, were protocols described for all regimens studied? Yes
  6.2. In observational study, were interventions, study settings, and clinicians/provider described? N/A
  6.2. In observational study, were interventions, study settings, and clinicians/provider described? N/A
  6.3. Was the intensity and duration of the intervention or exposure factor sufficient to produce a meaningful effect? Yes
  6.3. Was the intensity and duration of the intervention or exposure factor sufficient to produce a meaningful effect? Yes
  6.4. Was the amount of exposure and, if relevant, subject/patient compliance measured? Yes
  6.4. Was the amount of exposure and, if relevant, subject/patient compliance measured? Yes
  6.5. Were co-interventions (e.g., ancillary treatments, other therapies) described? Yes
  6.5. Were co-interventions (e.g., ancillary treatments, other therapies) described? Yes
  6.6. Were extra or unplanned treatments described? Yes
  6.6. Were extra or unplanned treatments described? Yes
  6.7. Was the information for 6.4, 6.5, and 6.6 assessed the same way for all groups? Yes
  6.7. Was the information for 6.4, 6.5, and 6.6 assessed the same way for all groups? Yes
  6.8. In diagnostic study, were details of test administration and replication sufficient? N/A
  6.8. In diagnostic study, were details of test administration and replication sufficient? N/A
  7. Were outcomes clearly defined and the measurements valid and reliable? Yes
7. Were outcomes clearly defined and the measurements valid and reliable? Yes
  7.1. Were primary and secondary endpoints described and relevant to the question? Yes
  7.1. Were primary and secondary endpoints described and relevant to the question? Yes
  7.2. Were nutrition measures appropriate to question and outcomes of concern? Yes
  7.2. Were nutrition measures appropriate to question and outcomes of concern? Yes
  7.3. Was the period of follow-up long enough for important outcome(s) to occur? Yes
  7.3. Was the period of follow-up long enough for important outcome(s) to occur? Yes
  7.4. Were the observations and measurements based on standard, valid, and reliable data collection instruments/tests/procedures? Yes
  7.4. Were the observations and measurements based on standard, valid, and reliable data collection instruments/tests/procedures? Yes
  7.5. Was the measurement of effect at an appropriate level of precision? Yes
  7.5. Was the measurement of effect at an appropriate level of precision? Yes
  7.6. Were other factors accounted for (measured) that could affect outcomes? Yes
  7.6. Were other factors accounted for (measured) that could affect outcomes? Yes
  7.7. Were the measurements conducted consistently across groups? Yes
  7.7. Were the measurements conducted consistently across groups? Yes
  8. Was the statistical analysis appropriate for the study design and type of outcome indicators? Yes
8. Was the statistical analysis appropriate for the study design and type of outcome indicators? Yes
  8.1. Were statistical analyses adequately described and the results reported appropriately? Yes
  8.1. Were statistical analyses adequately described and the results reported appropriately? Yes
  8.2. Were correct statistical tests used and assumptions of test not violated? Yes
  8.2. Were correct statistical tests used and assumptions of test not violated? Yes
  8.3. Were statistics reported with levels of significance and/or confidence intervals? Yes
  8.3. Were statistics reported with levels of significance and/or confidence intervals? Yes
  8.4. Was "intent to treat" analysis of outcomes done (and as appropriate, was there an analysis of outcomes for those maximally exposed or a dose-response analysis)? N/A
  8.4. Was "intent to treat" analysis of outcomes done (and as appropriate, was there an analysis of outcomes for those maximally exposed or a dose-response analysis)? N/A
  8.5. Were adequate adjustments made for effects of confounding factors that might have affected the outcomes (e.g., multivariate analyses)? Yes
  8.5. Were adequate adjustments made for effects of confounding factors that might have affected the outcomes (e.g., multivariate analyses)? Yes
  8.6. Was clinical significance as well as statistical significance reported? Yes
  8.6. Was clinical significance as well as statistical significance reported? Yes
  8.7. If negative findings, was a power calculation reported to address type 2 error? N/A
  8.7. If negative findings, was a power calculation reported to address type 2 error? N/A
  9. Are conclusions supported by results with biases and limitations taken into consideration? Yes
9. Are conclusions supported by results with biases and limitations taken into consideration? Yes
  9.1. Is there a discussion of findings? Yes
  9.1. Is there a discussion of findings? Yes
  9.2. Are biases and study limitations identified and discussed? Yes
  9.2. Are biases and study limitations identified and discussed? Yes
  10. Is bias due to study's funding or sponsorship unlikely? Yes
10. Is bias due to study's funding or sponsorship unlikely? Yes
  10.1. Were sources of funding and investigators' affiliations described? Yes
  10.1. Were sources of funding and investigators' affiliations described? Yes
  10.2. Was the study free from apparent conflict of interest? Yes
  10.2. Was the study free from apparent conflict of interest? Yes