NC: Weight Management (2007-2008)

Study Design:
- Click here for explanation of classification scheme.
Quality Rating:
Research Purpose:

Primary: Describe and evaluate long-term efficacy (18 months from the end of treatment) of a new cognitive short-term weight reducing treatment program for obese patients.

Secondary: Examine impact of binge eating disorder (BED) on the treatment result.
Inclusion Criteria:
  • Obese (BMI at least 30kg per m2)
  • Female
  • On waiting list for non-surgical treatment at obesity unit
  • Respond “yes” to written query about participating in trial.
Exclusion Criteria:
  • Signs of active tumor disease
  • Pregnancy
  • Symptoms of psychosis.
Description of Study Protocol:
  • Recruitment: Recruited from waiting list for non-surgical treatment in the Obesity Unit at Karolinska Institutet at Huddinge University Hospital.
  • Design: Subjects randomized to Cognitive Treatment (CT) and Control (C) groups prior to being asked to respond to written query about their participation in study
  • Blinding used: None.


  • Treatment took place between 1998 and 1999
  • All subjects interviewed using questionnaire for determining anorexia and bulimia
  • Sample comprised six treatment and three control groups
  • Control group remained on Obesity Unit's waiting list
  • Treatment Group
    • Cognitive program followed a manual
    • Group-related cognitive program for 10 weeks for 30 hours (three hours per lesson)
    • Each lesson structured and arranged into four blocks: A, B, C and D
      • A: Administration of manual’s questions aimed at situations that influence subjects' eating behavior followed by group discussions
      • B: Group discussion of previous lesson's homework
      • C: Each lecture had a "theme" that supplied information from the field of cognitive psychology; content of all themes related to eating behavior
      • D: New homework to apply and examine lecture's content to subjects' daily-life activities.
    • Nutrition Program
      • Purpose: Offer subjects a diet program of 1,200kcal to 1,300kcal per day with the possibility for individual variation and no restrictions regarding forbidden foods
      • KEY: Support subjects' own choices and planning as to how they wish to use the program
      • During the first two to three weeks, subjects were encouraged to weigh ingredients in food, but otherwise use the same foods used before the treatment program
      • Nutrition program closely linked to questionnaire manual throughout treatment period so subjects could analyze eating behavior during each week
      • No booster treatment after 10-week treatment program.

Statistical Analysis

  • Student's T-statistic used to test differences between group means
  • Chi-square used to analyze differences in proportions between groups
  • Statistical significance set at P<0.05 (two-tailed).
Data Collection Summary:

Timing of Measurements

Study outset, at end of treatment, at six, 12 and 18 months post-treatment.

Dependent Variables

  • Weight (measured without shoes, in light clothing, on a calibrated scale)
  • Hospital personnel not participating in the study checked all final weight measures.

Independent Variables

  • Cognitive group and Nutrition Treatment program
  • Binge Eating Disorder impact on treatment result.

Control Variables

Remained on Obesity Unit's waiting list.

Description of Actual Data Sample:

Initial N

  • 132 obese females: CT=66; C=66
    • After randomization: 105 (CT=62; C=43)
    • N (at start and end of treatment): 100 (CT=57; C=43)
    • N (at six-month follow-up): CT=47; C=36 
    • N (at 12-month follow-up): CT=40; C=33
    • N (at 18-month follow-up): CT=34; C=31.

Mean Age

  • CT: 45.4 years (SD=9.8; range, 21 to 60)
  • C: 45.2 years (SD=11.3; range, 18 to 60).


Not stated.

Other Relevant Demographics

  • All subjects except two (one in CT and one in C) previously participated in numerous group or individual weight-loss programs
  • Majority of subjects self-characterized as "perpetual dieters"
  • No statistically significant differences observed between groups for:
    • Education (P=0.13)
    • Married or co-habitating (P=0.70)
    • Given birth (P=0.67)
    • Working full- or part-time (P=0.14).


Mean BMI: (CT=40.4; C=39.2).


Karolinska Institutet at Huddinge University Hospital, Stockholm, Sweden.

Summary of Results:


Weight (kg) at Baseline

Mean (SD)

Weight (kg) at 18 Months

Mean (SD)

Weight (kg) Difference

Mean (SD)


Binge Eater

Treatment Group (N=18)

115.5 (16.0)

104.3 (15.1)

-11.2 (11.6)


Controls (N=16)

109.0 (13.8)

112.0 (14.7)

+3.0 (7.0)

Non-Binge Eater

Treatment Group (N=16)

105.9 (15.1)

96.4 (16.2)

-9.6 (10.1)


Controls (N=15)

113.4 (17.3)

114.9 (22.4)

+1.5 (7.1)


Treatment Group (N=34)

111.0 (16.1)

100.6 (15.9)

-10.4 (10.8)


Controls (n=31)

111.1 (15.5)

113.4 (18.6)

+2.3 (7.0)

  • Included subjects who completed weighing in 18 months after end of treatment
  • Mean weights given for binge and non-binge eaters.

Other Findings

  • Of the 105 patients, 58 (55%) were diagnosed with BED
  • Of these 58, 34 (59%; 18 from CT group and 16 from C group) participated in 18 months' follow-up
  • Bulimia nervosa was diagnosed in three subjects in the CT group and none in C group.
Author Conclusion:
  • Results demonstrate the method is effective in treatment of obesity in subjects with or without BED
  • Results fail to support general view that obesity treatment always requires long-term programs in order to attain positive results.


Funding Source:
Government: Stockholm County Council's Resource Center for Eating Disorders
Reviewer Comments:
  • Inclusion and exclusion criteria were not clearly listed, leaving the reviewer to question if all criteria was reported in the article
  • No description of how randomization was done
  • Limitations not clearly stated
  • Potential conflict of interest: Study was financially supported by Stockholm County Council's Resource Centre for Eating Disorders.
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? 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? ???
  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? Yes
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 or comparisons used? (Concurrent preferred over historical control or comparison groups.) 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 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? 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? Yes
  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.) Yes
  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? 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)? N/A
  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? ???
  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? ???
  10.1. Were sources of funding and investigators' affiliations described? Yes
  10.2. Was the study free from apparent conflict of interest? ???