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Adult Weight Management

NC: Maintenance of Health/Behavior Change Following Short-term CBT (2008)

Citation:

Ryttig KR, Flaten H, Rossner S.  Long-term effects of a very low calorie diet (Nutrilett) in obesity treatment.  A prospective, randomized, comparison between VLCD and a hypocaloric diet + behavior modification and their combination.  Int J Obesity Relat Metab Disord 1997;21(7):574-9.

PubMed ID: 9226488
 
Study Design:
Randomized Controlled Trial
Class:
A - Click here for explanation of classification scheme.
Quality Rating:
Neutral NEUTRAL: See Quality Criteria Checklist below.
Research Purpose:
To compare weight loss on a balanced hypocaloric diet to that of a Very Low Calorie Diet after 2 months of treatment and to further compare 26 months of weight maintenance and safety with or without VLCD assistance in obese patients.
Inclusion Criteria:
  • Obese patients, BMI > 30
  • Able to complete a visual analog scale concerning hunger feelings at 3 pm daily during a 2-week run-in period
  • Between 21 - 64 years old
  • Stable body weight (fluctuations < 3 kg) within last 2 months before treatment
Exclusion Criteria:
  • Patients with known history of renal, cardiac, cerebrovascular, GI ulcer, or gallbladder diseases
  • Patients suffering from IDDM, gout, and porphyria
  • Patients with psychiatric disturbances such as depression, schizophrenia and behavior disorders such as alcoholism and drug abuse
  • Treatment with antihypertensives, antidepressants, anorectics and lithium, oral contraceptives, and estrogen therapy
  • Pregnancy and lactation
  • Vegetarian diet
  • Lack of informed consent
Description of Study Protocol:

Recruitment

Subjects had been on a waiting list of an obesity unit at Karolinska hospital.

Design

Prospective, randomized controlled intervention trial, initially with 2 and later with 3 parallel groups.

Blinding used (if applicable)

Not used.

Intervention (if applicable)

  • One group randomized to balanced diet of 6720 kJ/day (1600 kcal/day) during whole treatment period (Group A)
  • One group randomized to VLCD, Nutrilett of 1764 kJ/day (420 kcal/day) for first 2 months, then rerandomized hypocaloric balanced diet (1600 kcal/day) with (Group C) or without (Group B) 1 MJ of VLCD to be taken during the evening

Statistical Analysis

ANOVA at different times was used to analyze efficacy data such as weight reduction, fat and FFM.  Subgroup analyses were made for the patients completing the 12 months and the 26 months follow-up respectively.

Data Collection Summary:

Timing of Measurements

Body weight, blood pressure and heart rate measured and side-effects of treatment assessed by interview every week during the first month, then every second week during the following month, monthly during the next seven months and finally every seventh week during the rest of the observation period.

Dependent Variables

  • Body weight measured on scale
  • Body composition measured using bioelectrical impedance
  • 12-lead resting ECG
  • Serum electrolytes, blood glucose, fasting lipids, and urine tests 

Independent Variables

  • One group randomized to balanced diet of 6720 kJ/day (1600 kcal/day) during whole treatment period (Group A)
  • One group randomized to VLCD, Nutrilett of 1764 kJ/day (420 kcal/day) for first 2 months, then rerandomized hypocaloric balanced diet (1600 kcal/day) with (Group C) or without (Group B) 1 MJ of VLCD to be taken during the evening
  • Eating habits and dietary compliance checked by RD interviews

Control Variables

 

Description of Actual Data Sample:

Initial N: 81 subjects, 44 female, 37 male.  27 randomized to balanced diet, 54 to VLCD

Attrition (final N):  4 VLCD subjects discontinued treatment prematurely.  39 subjects (22 females, 17 males) discontinued treatment before the 2 year follow up.

Age:  aged 21 - 64 years old

Ethnicity:  not mentioned

Other relevant demographics:

Anthropometrics:  There were no significant differences between groups randomized to balanced diet and VLCD at baseline.  Details were not given regarding differences between second randomization of VLCD group.

Location:  Sweden

 

Summary of Results:

Other Findings

During the first 2 month period, the mean body weight loss in the VLCD group was 18.9 +/- 7.1 kg compared to 7.2 +/- 4.8 kg in the diet treated group, with a similar relative fat loss assessed by bioimpedance of 68% and 76% respectively. 

The maintained weight loss in all groups after 28 months of treatment was 10.9 +/- 10.2 kg in the 52% who completed the programme.

Weight losses and drop-out rates were similar in all 3 groups. 

No changes in hunger feelings were noted.

There were no significant differences between groups in terms of blood and urine chemistry or blood pressure.

The overall results of this study demonstrate that after 2 years the mean values of body weight in the completers were between 7 - 10% below the respective pre-treatment values.

Author Conclusion:
Several obese patients have problems controlling overeating during the late afternoon and evening.  It may be hypothesized that a protein rich VLCD could prevent evening hyperphagia during the weight maintenance period.  Free use of 1 MJ/day had however no influence on body weight in our study.  It is possible that instructions for future use of single VLCD sachets must be tailored individually and much more in detail than intended with this study.
Funding Source:
Industry:
Nycomed Pharmaceutical
Pharmaceutical/Dietary Supplement Company:
Reviewer Comments:
Details of second randomization of VLCD group not provided and subject groups not described.  Power analysis not completed. 
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? 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? Yes
3. Were study groups comparable? ???
  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? ???
  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? ???
  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? ???
  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? 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)? N/A
  8.5. Were adequate adjustments made for effects of confounding factors that might have affected the outcomes (e.g., multivariate analyses)? Yes
  8.6. 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? No
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? ???
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