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Citation:

Williamson DA, Martin PD, White MA, Newton R, Walden H, York-Crowe E, Alfonso A, Gordon S, Ryan D. Efficacy of an internet-based behavioral weight loss program for overweight adolescent African-American girls. Eat Weight Disord. 2005 Sep;10(3):193-203.


PubMed ID: 16277142
Study Design:
Randomized Controlled Trial
Class:
A - Click here for explanation of classification scheme.
POSITIVE: See Research Design and Implementation Criteria Checklist below.
Research Purpose:

To compare the efficacy of an interactive Internet-based behavioral weight management program to a passive Internet-based health education program in overweight adolescent African-American girls (BMI > 85th percentile; age 11-15 years) who have at least 1 obese biological parent (BMI > 30).

Inclusion Criteria:
  • African-American girls age 11 to 15 at risk for overweight (BMI > 85th percentile for age and gender) with at least one obese biological parent (BMI > 30) and an overweight parent (BMI >27) who was willing to participate in the study
  • The adolescent's family was willing to use a $700 coupon to purchase a computer for the study and to pay $300 out-of-pocket expenses toward the purchase
  • The family's home had electricity and at least one working telephone line.
Exclusion Criteria:
  • Adolescent or parent had insulin-dependent diabetes, an eating disorder, a significant mental health problem, or a serious health problem
  • Pregnancy, for either adolescent or parent
  • Other problems were present that would interfere with successful completion of the study. 
Description of Study Protocol:

Recruitment

A media and advertising campaign used talks in the community, paid advertisements, printed stories in newspapers and magazines, and radio and television appearances. No data about socioeconomic status was collected at screening; participants were just asked about their ability to put $300 towards purchasing a computer.

Design:  Randomized controlled trial

  • Adolescent participants were randomly assigned to either a control program, which was very passive, or a behavioral program, which was highly interactive, using a stratified randomization strategy.
  • Participants were stratified in the treatment assignment based on BMI percentile and age.
  • Two websites were designed to present culturally-specific nutrition and physical activity information; participants were only able to access the Website appropriate for their treatment group.
  • The control program included non-targeted education on nutrition and physical activity, while the treatment program received nutrition education and a behavior modification program targeting the eating and exercise habits of the overweight adolescents and parents.
  • Each family was assigned a counselor who conducted face-to face sessions at weeks 1, 3, 6, and 12 and corresponded regularly using email.
  • For the behavioral group, the sessions focused on goal-setting and coordinated with modules on the Website corresponding to the same goals.
  • The control group received nutrition education from a Registered Dietitian but were not prescribed behavioral changes to yield weight loss.
  • The control Website was non-interactive and provided health education for parents and adolescents.
  • Assessment measures were done at baseline and at 6 months post-baseline. Overall participation in both interventions was measured via "hits" per person during the 6-month intervention. 
  • Utilization of specific components of the program (completion of weekly quizzes, percent correct answers, number of emails to counselors, submission of body weight and minutes of exercise) was also tracked for the behavioral group.  

Blinding used

None mentioned for participants; personnel collecting measurements for assessments were not blinded to the treatment assignment or the families.

Intervention

The behavioral group (treatment group) received a prescribed, targeted behavioral modification program and Internet counseling targeting lifestyle eating and physical activity habits of the participants. This group attended four in-person sessions focused on:

  • Food monitoring and goal setting for intake
  • Monitoring exercise and setting a goal of > 150 minutes of exercise per week by week 20
  • Behavioral Contracting and modeling appropriate strategies
  • Reviewing progress and problem-solving for poor adherence.

The sessions coordinated with modules on the Website and corresponded with the same goals.

Statistical Analysis

Analysis of variance was done on the change from baseline values. Pearson Product Moment Correlations were calculated between variables to test for linear relationships.

Data Collection Summary:

Timing of Measurements

Data were collected at baseline and at 6 months.

Dependent Variables

The following data were collected at baseline and at 6 months:

  • BMI
  • Body weight
  • Body composition (determined using DEXA)
  • Nutrient intake (determined by using both 24-hour recall and Block FFQ)
  • Weight loss behaviors (determined by Weight Loss Behavior Scale,Child Dietary Self-Efficacy Scale, Physical Activity Social Support, and Children's Eating Attitudes Test). 

Independent Variables

  • An interactive internet-based behavioral program providing prescribed changes and targeted information for eating and exercise.

Control Variables

Low-cost computers and free internet access were provided to participants in both treatment groups.

Description of Actual Data Sample:

Initial N: 57 adolescent girls and their parents

Attrition (final N): 50 adolescent girls (88%) and their parents completed assessment at 6 months.

Age: Adolescent girls were age 11 to 15; age of parents was not described.

Ethnicity: African-American

Other relevant demographics:

Anthropometrics: The average BMI  percentile for the adolescent girls was 98.3 percentile. Parents had a BMI range of 28.9 to 57.8 kg/m2 and body fat percent range from 30.8 to 63.6 percent. Groups did not differ (P>0.05) on any of these measures at baseline.

Location: United States

 

Summary of Results:

Key Findings

  • Adolescent girls in the two groups approached statistically significant differences for BMI at 6 months (P=0.057).
  • In comparison with the control condition, adolescents in the behavioral program lost more mean body fat (-1.12 ± 0.47% vs 0.43 ± 0.47% body fat, P < 0.05) and parents in the behavioral program lost significantly more mean body weight (-2.43 ± 0.66 vs -0.35 ± 0.64 kg, P < 0.05) during the first six months, but this weight was regained over the next 18 months.
  • Group differences for adolescent body weight changes also approached statistical significance (P=0.055). Parents in the two groups differed for changes in BMI but not in terms of changes in body fat; changes were not statistically significant.
  • Based on the Block Food Frequency Questionnaire, adolescents in the behavioral group reduced total daily energy intake (P<0.001), while energy intake for the control group did not change significantly from baseline. This pattern was similar for parents as well.
  • The behavioral program website was associated with significantly greater participation by adolescents (P<0.001) and parents (P<0.001). The number of website "hits" by parents and adolescents were positively correlated (P<0.001).
  • In the behavioral group, change in body fat was negatively correlated with the number of email submissions to Internet counselors (P<0.05), percent correct answers on weekly quizzes (P<0.05), and number of submissions of body weight for the weight graph component (P<0.05). 
  • After 2 years, differences in fat for adolescents (-0.08 ± 0.71% vs 0.84 ± 0.72% body fat) and weight for parents (-1.1 ± 0.91 vs -0.60 ± 0.89 kg) did not differ between the behavioral and control programs.

 

Author Conclusion:

These preliminary findings are useful to demonstrate that an internet-based weight management program can yield statistically significant (but not necessarily clinically significant) weight and/or fat losses in obese adults and overweight adolescents. An internet-based weight management program may be more appropriate for overweight individuals who need to lose a small amount of weight, and may be a useful strategy to prevent weight gain in children, adolescents, or adults. The findings suggest a higher level of adolescent participation was associated with greater fat loss; in addition, parent participation was positively correlated with child participation. Further developments of internet applications for health behavior change are warranted.

Reviewer Comments:

Limitations of this study are its small sample size and lack of blinding for personnel conducting measurements at the assessment points. The authors state that this study should be viewed as a test of weight-loss induction, not long-term weight maintenance.


Research Design and Implementation 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
  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 nutrition or dietetics practice?
Yes
  4. Is the intervention or procedure feasible? (NA for some epidemiological studies)
Yes
 
Validity Questions
1. Was the research question clearly stated?
Yes
  1.1. 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
  1.3. Were the target population and setting specified?
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
  2.2. Were criteria applied equally to all study groups?
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?
???
3. Were study groups comparable?
Yes
  3.1. Was the method of assigning subjects/patients to groups described and unbiased? (Method of randomization identified if RCT)
Yes
  3.2. Were distribution of disease status, prognostic factors, and other factors (e.g., demographics) similar across study groups at baseline?
Yes
  3.3. Were concurrent controls used? (Concurrent preferred over historical controls.)
Yes
  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 or cross-sectional 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. Criterion may not be applicable in some cross-sectional studies.)
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
  4.1. 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
  4.3. Were all enrolled subjects/patients (in the original sample) accounted for?
Yes
  4.4. Were reasons for withdrawals similar across groups?
???
  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?
No
  5.1. In intervention study, were subjects, clinicians/practitioners, and investigators blinded to treatment group, as appropriate?
No
  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.)
No
  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
  5.5. 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
  6.1. 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
  6.3. 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
  6.5. Were co-interventions (e.g., ancillary treatments, other therapies) 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
  6.8. 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
  7.1. 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
  7.3. 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
  7.5. 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
  7.7. Were the measurements conducted consistently across groups?
Yes
8. Was the statistical analysis appropriate for the study design and type of outcome indicators?
Yes
  8.1. 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
  8.3. 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)?
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
  8.7. 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
  9.1. Is there a discussion of findings?
Yes
  9.2. Are biases and study limitations identified and discussed?
Yes
10. Is bias due to study’s funding or sponsorship unlikely?
Yes
  10.1. Were sources of funding and investigators’ affiliations described?
Yes
  10.2. Was the study free from apparent conflict of interest?
Yes
 
 

Copyright American Dietetic Association (ADA).