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MNT: Weight Management (2015)

Citation:

Jensen GL, Roy M, Buchanan AE, Berg MB. Weight loss intervention for obese older women: I mprovements in performance and function. Obes Res. 2004; 12(11): 1,814-1,820.

PubMed ID: 15601977
 
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 determine the feasibility of a three-month weight loss program for older, obese, community-dwelling women and compare before and after measures for:
  • Anthropometrics
  • Laboratory results
  • Physical performance
  • Functionality
  • Quality of life.
Inclusion Criteria:
  • At 60 years of age or more
  • At 30kg/m2 or more
  • Community dwelling
  • Ambulatory
  • Having a phone
  • Expected to live 12 months or more
  • Signed informed consent.
Exclusion Criteria:
None specifically stated.
Description of Study Protocol:

Recruitment

Local print, electronic and TV advertisements used to recruit subjects in Nashville, TN.

Design

  • Pre- intervention and post-intervention
  • No control group.

Intervention

  • Free three-month weight loss program consisting of a prudent diet, behavior modification and physical activity. A baseline and follow-up assessment were conducted by a bariatric physician and eight counseling sessions were provided by a dietitian (30 minutes each) between baseline and completion of the program. Participants were encouraged to:
    • Reduce caloric intake to 1,200kcal to 1,500kcal per day
    • Take multi-vitamins with minerals and calcium and vitamin D supplements
    • Consume two to three servings of calcium-rich foods per day
    • Consume foods high in B12 and folic acid
    • Keep a food diary for duration of study
    • Keep an activity diary (steps per day) for the duration, with a target of 5,000 steps per day.
  • A dietitian reviewed food and activity diaries with each participant at each visit and developed new goals based on reports from the diaries. Weight loss goal was a 5% reduction in weight. All education materials were available in large font, with an eight-grade reading level.

Statistical Analysis

  • Descriptive statistics for continuous and categorical data
  • A Wilcoxon Signed Rank test was used to compare continuous pre-outcome and post-outcome measures
  • A McNemar test was used to compare change in paired categorical outcome measures.
Data Collection Summary:

Timing of Measurements

Assessments were completed at baseline and the three-month follow-up visit. They included
  • Laboratory:
    • Lipid panel
    • FBG
    • HbA1C.
  • Anthropometric:
    • Height
    • Weight
    • Fat mass or fat-free mass via BIA.
  • Functional: Seven performance measures
  • Quality-of-life assessments:
    • SF-36
    • Life Space Assessment (LSA).

Dependent Variables

  • Weight: Reported in kg; taken on a digital scale without over-garments or shoes
  • Height: Wall-mounted stadiometer
  • Lipid panel:
    • Total cholesterol
    • LDL-C
    • HDL-C
    • TG.
  • Body composition: Bioelectrical impedance (BIA) was used to estimate fat and fat-free mass
  • Physical performance: Seven tests were used and scored on a four-point scale (range zero to 28), with a high score being a better performance
  • Step counts: Pedometer
  • Health status:
    • Short-Form 36 Health Status Survey (SF-36): Measures eight domains
    • Life Space Assessment (LSA): Provides assessment of mobility and functioning.

Independent Variables

The three-month intervention.

Control Variables

Dietary intake was assessed by the dietitian within two weeks of baseline assessment using three non-consecutive 24-hour recalls obtained via phone. The multiple-pass approach was used and visual aids were given to participants. NDS-R was used for analysis. The three recalls were averaged and used to assess adequacy of baseline nutrient intake compared to the DRI.

 

Description of Actual Data Sample:
  • Initial N: A total of 26 females
  • Attrition (final N): A total of 18 (31% attrition). There were no statistically significant differences at baseline between study completers and those who withdrew except for the number of medications taken [completers 7.5 (SD 3.1) and non-completers = 6.9 (SD 6.9)]
  • Age: Mean (SD) = 64.1 years (4.8)
  • Ethnicity:
    • Non-Hispanic white: A total of 16/18 (89%)
    • African American: A total of 2/18 (11%).
  • Other relevant demographics:
    • Education level: High school or more
    • Mean number of co-morbidities at baseline: 3.2 (1.3)
    • Mean caloric intake = 1,785kcal (467)
    • All DRIs were met except for fiber and vitamin D.
  • Anthropometrics: Mean baseline BMI of  39.1kg/m2 (6.6 kg/m2)
  • Location: Nashville, TN.

 

Summary of Results:


 

Measure Baseline Three-month Follow-up P-value
Weight, kg (SD) 100.4 (15.5) 96.1 (17.8) 0.006
BMI, kg/m2 (SD) 39.1 (6.6) 37.6 (7.7) 0.008
FFM, kg (SD) 46.6 (3.4) 45.3 (4.5) 0.019
FM, kg (SD) 54.2 (13.1) 51.1 (14.0) 0.015
Systolic blood pressure, mm Hg (SD) 130.6 (15.8) 126.0 (8.9) 0.306
Diastolic blood pressure, mm Hg (SD) 84.4 (6.5) 78.9 (6.2) 0.043
Total cholesterol, mg per dL (SD) 204.6 (33.2) 192.5 (38.3) 0.042
HDL-C, mg per dL (SD) 65.0 (17.0) 61.8 (14.4) 0.422
LDL-C, mg per dL (SD) 112.5 (30.6) 107.2 (40.5) 0.308
TG, mg per dL (SD) 136.4 (51.5) 124.1 (59.2) 0.026
Step count, mean (SD) 4,027 (2515) 5,883 (3214) 0.015
Physical performance score, mean (SD) 21.6 (4.5) 22.7 (4.2) 0.026
SF-36 general health, mean (SD) 62.2 (17.8) 67.8 (19.3) 0.119
LSA Independent life space, N (%) 14.9 (77.8) 15 (83.3) 1.0



 

 

Author Conclusion:
It is feasible for obese older women to achieve moderate weight loss and increase activity level to effect a change in laboratory values, physical performance, self-reported functioning and quality-of-life measures.
Funding Source:
Reviewer Comments:
Limitations
  • Selection bias
  • Lack of control group
  • More than 30% withdrawal
  • An inability to generalize findings.
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? No
  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? 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? No
  2.2. Were criteria applied equally to all study groups? N/A
  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? 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.) N/A
  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? N/A
  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? N/A
  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? N/A
  6.1. In RCT or other intervention trial, were protocols described for all regimens studied? No
  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? No
  6.5. Were co-interventions (e.g., ancillary treatments, other therapies) described? No
  6.6. Were extra or unplanned treatments described? No
  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? 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? 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)? 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? Yes
  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