MNT: Weight Management (2015)
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
- BMI 28kg/m2 or more
- Approval from a medical practitioner.
Local newspaper used to recruit participants.
- Pre-experimental before and after design
- No control group
- Measures were taken at baseline and six months later.
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.
- 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.
Timing of Measurements
Baseline to six months.
- 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.
A standardized online instruction incorporating low GL foods and cognitive behavioral strategies as explained above.
- 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.
- 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.
Christchurch, New Zealand.
|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|
- 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).
- Large dropout rate
- No control group
- Many potential confounders
- Self-report nature of outcome variables.
Quality Criteria Checklist: Primary Research
|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|
|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|