Adult Weight Management

AWM: Meal Replacements (2006)

Citation:

Ahrens RA, Hower M, Best AM.  Effects of weight reduction interventions by community pharmacists.  J Am Pharm Assoc 2003; 43: 583-589.

 
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 a meal replacement program with a conventional reduced-calorie diet for weight management using the pharmacy as the setting and the pharmacist as the point of contact for dietary advice.
Inclusion Criteria:

Eligible if BMI between 25 - 32, age 35 - 65 years, obtained physician's approval, and indicated that the taste of the shake was acceptable.

Exclusion Criteria:
Excluded if they had known hypersensitivity to liquid meal replacement product, had type 1 or type 2 diabetes mellitus or fasting blood glucose level +/- 126 mg/dl, had history of coronary artery disease, had stage 3 hypertension, were taking a tricyclic antidepressant, megestrol acetate, phenothiazine or oral corticosteroid, were pregnant or breast feeding, or had participated in any investigational trial within the previous 30 days.
Description of Study Protocol:

Recruitment

Recruited through radio, print and in-store advertising.

Design

Randomized, controlled, open-label trial.

Blinding used (if applicable)

Not used.

Intervention (if applicable): 

Block randomized to meal replacement plan or traditional reduced-calorie diet plan.

Statistical Analysis

Two-group t tests were used to compare the treatment effect in all eligible patients and in all active-period patients.  Patients were deemed eligible if they completed the first 2 weeks of the study.  Active-period patients were defined as those continuing through week 12.  A mixed-model repeated measures ANOVA was performed to compare the 2 groups, using all of the weight data collected through 12 weeks.  2 analyses of "successful weight loss" (defined as weight loss greater than 7%) were performed:  a 2 x 2 contingency table analysis using the Fisher exact test for all eligible patients and a similar analysis using all active-period patients.  For the weight maintenance data: an independent groups t test using all maintenance patients, an independent groups t test using all active-period patients (last observation carried forward), and a mixed-model analysis comparing the 2 groups using all of the weight data collected on any patient.  To compare the 7 efficacy variables, a mixed-model analysis was used to compare the amount of change from baseline between the 2 treatment groups. 

Data Collection Summary:

Timing of Measurements

After randomization, patients were followed for 12-week period of active weight loss and 10-week period of weight maintenance.  Patients returned every 3 weeks for 15-min follow-up with the pharmacist for a total of 13 visits, during which pharmacists measured weight, waist circumference and blood pressure, as well as complete a basic survey to assess patient dietary adherence, levels of well-being, and identify program problems.

Dependent Variables

  • Body weight
  • Blood pressure assessed while sitting after 5 min rest using computerized DynaPulse system
  • Full blood lipid panels performed using Cholestech LDX analyzer
  • Blood glucose measured using OneTouch Fast Take monitor
  • Waist circumference measured at natural waist on bare skin

Independent Variables

  • Meal replacements or reduced-calorie diet interventions.  Meal replacement group followed self-selected diet with 2 of 3 meals replaced with Slim Fast shake (220 calories, 7 - 10 g protein, 40 - 46 g carbohydrate, 1.5 - 3 g fat).  Subjects received meal replacements for free.  Reduced-calorie diet group used self-selected diet based on diabetic exchanges.  In both groups, women were prescribed 1200 kcals/day, men 1500 kcals/day.  RD reviewed the plan and was consulted as needed.  During weight maintenance, subjects not restricted to defined caloric intake.  Meal replacement subjects consumed 1 shake per day in weight maintenance.  Both groups were encouraged but not required to keep food and activity diaries.
  • Questionnaires validated by American Dietetic and American Diabetes Associations completed during initial visit, including basic questions about weight loss history, current diet, and present level of physical activity.  Pharmacists briefly trained subjects in lifestyle modifications using information sheets about proper nutrition, physical activity, and behavior modification.

Control Variables

 

Description of Actual Data Sample:

Initial N: 95 enrolled, 83 women, 12 men

Attrition (final N):  88 were considered eligible for comparison by continuing through week 2 of study.  68 (72%) completed active weight loss phase, and 55 (58%) completed weight maintenance phase.  12 dropped out due to time constraints, 2 could not tolerate the meal replacement, 1 could not adhere to reduced-calorie diet regimen, 1 self-excluded due to weight gain.

Age:  Meal replacements (n=45):  mean age 47.6 +/- 7.9 years, Reduced-calorie diet (n=43):  mean age 47.8 +/- 9.5 years  

Ethnicity:  Not mentioned. 

Other relevant demographics:  All subjects from southwestern Iowa or southeastern Nebraska 

Anthropometrics:  No significant differences between groups on baseline characteristics:  height, weight, age, BMI, waist circumference, DBP, SBP, TC, triglycerides, LDL-cholesterol or HDL-cholesterol.

Location:  Travis Pharmacy in Shenandoah, Iowa 

 

Summary of Results:

 

MR 0-12 weeks MR 12-22 weeks RCD 0-12 weeks RCD 12-22 weeks

Body Weight (kg)

4.90 +/- 0.30 0.70 +/- 0.40 4.30 +/- 0.30 0.90 +/- 0.40
Waist Circumference (cm) -5.31 -8.08 -6.10 -7.82
Systolic BP (mm Hg) -5.91 -8.26 -6.48 -7.81
Diastolic BP (mm Hg) -4.16 -5.97 -4.23 -4.30

Total Cholesterol (mg/dl)

-11.95

4.74

-7.28

0.27

Triglycerides (mg/dl) -0.08 0.00 -0.19 -0.20
LDL-Cholesterol (mg/dl) -8.86 1.15 -1.37 3.79

HDL-Cholesterol (mg/dl)

-0.19

4.44

-0.93

1.38

Other Findings

During active weight loss phase, the meal replacement and reduced calorie diet groups lost a significant amount of weight, although no significant difference was found between the groups (meal replacement:  4.90 +/- 0.30 kg, reduced-calorie diet:  4.30 +/- 0.30 kg, P = 0.16).

In weight maintenance phase, no statistically significant difference was found between the groups:  meal replacement group lost 0.70 +/- 0.40 kg and the reduced-calorie diet group lost 0.90 +/- 0.40 kg (P = 0.60).

Significant improvements were observed in waist circumference, systolic and diastolic blood pressure, and triglyceride levels.

No significant changes were seen in HDL-cholesterol or LDL-cholesterol levels in either group.

Author Conclusion:
Successful weight management can be achieved in a pharmacy setting.  Both meal replacement and reduced-calorie diet programs were effective methods for weight loss and the maintenance of that loss over a 22-week period.
Funding Source:
Industry:
Slim-Fast
Food Company:
Reviewer Comments:
Food and activity diaries encouraged but not required.  No analysis of caloric intake.  Only 10 week duration of maintenance phase.
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? 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? ???
  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%.) ???
  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? 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? ???
  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? ???
  6.4. Was the amount of exposure and, if relevant, subject/patient compliance measured? ???
  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? ???
  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? ???
  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? ???
  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? 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? Yes
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