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MNT: Weight Management (2015)

Citation:

Collinson A, Lindley R, Campbell A, Waters I, Lindley T, Wallace A. An evaluation of an Internet-based approach to weight loss with low glycaemic load principles. J Hum Nutr Diet. 2011; 24:192-195.

 

 

PubMed ID: 21843154
 
Study Design:
Before-After Study
Class:
D - Click here for explanation of classification scheme.
Quality Rating:
Neutral NEUTRAL: See Quality Criteria Checklist below.
Research Purpose:
To investigate the efficacy of an Internet-based weight-loss program that incorporates low glycemic (GL) principles, cognitive behavioral strategies and interaction with a dietitian and peers for support. 
Inclusion Criteria:
  • BMI 28kg/m2 or more
  • Approval from a medical practitioner.
Exclusion Criteria:
Existence of a chronic disease.
Description of Study Protocol:

Recruitment

Local newspaper used to recruit participants.

Design

  • Pre-experimental before and after design
  • No control group
  • Measures were taken at baseline and six months later.

Intervention

Participants received standardized online instruction to consume an energy-restricted diet incorporating low GL foods. The New Zealand Heart Foundation food pyramid served as a guide for recommendations and participants were encouraged to consume two servings of beans and legumes and one serving of protein daily. Physical activity was encouraged. A bi-weekly chat room with a dietitian and peers was provided and cognitive behavioral strategies such as stimulus control, problem solving, goal setting and coping with negative thoughts were incorporated into the program.

Statistical Analysis

  • A paired T-test was used to assess weight change from baseline to six months
  • Mann-Whitney U and chi square tests were used to assess differences in clinically significant weight loss (more than 5% of their body weight at baseline) and use of the chat room, whether they self-reported their weight loss, whether they had greater self-reported energy levels and better exercise scores
  • Wilcoxon-signed rank was used to compare differences in the amount of food groups within participants baseline to six months.
Data Collection Summary:

Timing of Measurements

Baseline to six months.

Dependent Variables

  • Weight loss: Height, weight and waist circumference were measured at baseline and six months by a trained researcher
  • Food intake: Self-reported using online food records to report foods and serving sizes
  • Energy levels, satiety levels and exercise habits: Also self-reported online at baseline and six months.

Independent Variables

A standardized online instruction incorporating low GL foods and cognitive behavioral strategies as explained above.

Description of Actual Data Sample:
  • Initial N: N=103 participants (71 female, 32 male)
  • Attrition (final N): N=70 participants (47 female, 23 males); 32% attrition
  • Age: Mean (SD) age was 45.5 years (11.4 years) of final 70 participants.

Anthropometrics

  • BMI categories:
    • 28 to 29.9: N=7 (10%)
    • 30 to 34.9: N=28 (40%)
    • 35 to 39.9: N=27 (39%)
    • More than 40: N=8 (11%).
  • Mean (SD) waist circumference: 109.6 (13.8)
  • No statistical differences in baseline characteristics at baseline between total sample and those who completed the study.

Location

Christchurch, New Zealand.

Summary of Results:

Key Findings

Variable Baseline
Mean (SD)
Six Months
Mean (SD)
Change
Mean (CI)
P-value
Weight (kg) 99.7 (15.6) 96.2 (15.9) 3.5 (2.3 to 4.7) 0.001
BMI 35.5 (4.8) 34.2 (5.1) 1.2 (0.8 to 1.7) 0.001
Waist circumference (cm) 109.6 (13.8) 104.8 (13.0) 4.8 (2.8 to 6.8) 0.001

Other Findings

  • After six months:
    • A total of 51 (73%) lost weight
    • A total of 25 (36%) lost a clinically significant amount (more than 5%)
    • A total of 19 (27%) gained weight.
  • A total of 35 (50%) used the chat room and lost more weight than non-users (4.8kg vs. 2.2kg, P=0.036)
  • Participants who lost a clinically significant amount of weight were more likely to enter self-reported weights (P=0.014), were more likely to use the chat room (P=0.037) and reported greater energy levels (P=0.035) than those not losing as much weight
  • No differences in reported exercise activity was found
  • A total of 90% made at least one positive dietary change; 74% and 47% increased fruit and vegetables, respectively. Legume intake significantly increased in 79% of participants (P<0.001) and 39% decreased their meat intake (P<0.001).
Author Conclusion:
An Internet-based weight-loss program is a successful method to promote weight loss.
Funding Source:
Industry:
Lifestyle Foods for Energy Balance
Not-for-profit
The New Zealand Foundation for Research Science and Technology
Reviewer Comments:
  • Large dropout rate
  • No control group
  • Many potential confounders
  • Self-report nature of outcome variables.
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
  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
  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? No
2. Was the selection of study subjects/patients free from bias? No
  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? No
  2.4. Were the subjects/patients a representative sample of the relevant population? No
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
  3.2. 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.) No
  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
  3.6. 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? No
  4.1. Were follow-up methods described and the same for all groups? No
  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? No
  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? 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.) 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
  5.5. 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? N/A
  6.6. Were extra or unplanned treatments described? N/A
  6.7. Was the information for 6.4, 6.5, and 6.6 assessed the same way for all groups? 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
  7.1. 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? ???
  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? No
  7.7. Were the measurements conducted consistently across groups? N/A
8. Was the statistical analysis appropriate for the study design and type of outcome indicators? No
  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)? No
  8.5. Were adequate adjustments made for effects of confounding factors that might have affected the outcomes (e.g., multivariate analyses)? No
  8.6. Was clinical significance as well as statistical significance reported? No
  8.7. If negative findings, was a power calculation reported to address type 2 error? No
9. Are conclusions supported by results with biases and limitations taken into consideration? No
  9.1. Is there a discussion of findings? Yes
  9.2. Are biases and study limitations identified and discussed? No
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