EAL

NC: Group vs. Individual Counseling (2007)

Citation:

Study Design:

Class:

- Click here for explanation of classification scheme.

Quality Rating:

Research Purpose:

This study was designed to answer two main questions regarding diet and weight loss in moderately overweight and obese subjects:

Can a primary care physician implement a successful long-term lifestyle change using meal replacements within time constraints existing in the general office practice of medicine?
Can a traditional lifestyle-modification program administered by a registered dietitian using a meal-replacement strategy be as effective as the same program using a standard food plan exchange strategy.
A further aim of this study is to evaluate the potential health benefits of sustained weight loss for specific chronic disease risk factors associated with the moderately overweight and obese.

Inclusion Criteria:

113 overweight or obese, pre-menopausal women, aged 25 to 50 years (average age 41.4±4.7 years) with BMI between 25 and 35kg/m²

Exclusion Criteria:

Current chronic or psychological disease
Abnormal serum laboratory values of clinical significance
Current hormone replacement therapies
Pregnant or plans to become pregnant
Lactating
Plans to move out of the area within the following year.

Description of Study Protocol:

Recruitment

Media announcements and fliers distributed in the local community.

Design

Subjects were randomly assigned to three different intervention groups. At baseline and one year, all subjects were assessed for weight, height, BMI, waist circumference, Resting Energy Expenditure (kcal per 24 hours), blood pressure, and fasting serum chemistries including: Lipid, insulin and glucose values. Changes in these parameters and relationships between weight change and other parameters were evaluated.

Intervention

All subjects attended a total of 26 sessions during the one-year study and received instruction manuals that included lessons based on Lifestyle, Exercise, Attitude, Relationships and Nutrition (LEARN Program for Weight Control). A new intervention lesson was distributed at each session. Diet instruction included a low-calorie diet of approximately 1,200kcal per day with up to 30% kcal as fat, using the USDA food guide pyramid food groups and portion sizes to ensure adequate nutrients and a variety of foods. Activity instruction as a method of self-motivation included increasing energy expenditure by walking up to 10,000 steps a day as measured by a pedometer. The three different lifestyle based intervention groups included:

Traditional Dietitian-Led Intervention Group: Subjects attended a total of 26 small classes (eight to ten subjects per class); classes were weekly for three months, bi-weekly for the second three months and monthly for the final six months. Diet consisted of all meals and snacks prepared from self-selected conventional foods following 1,200kcal per day, using USDA food pyramid.
Traditional Dietitian-Led Intervention Group incorporating Meal Replacements: Subjects attended a total of 26 small classes as in group one. Two of the three main meals each day consisted of meal replacement shakes or bars, each containing 220kcal, eight grams protein, 33g to 36g carbohydrate, five grams fat and two grams dietary fiber plus 25% to 35% of daily value for essential vitamins and minerals.
Primary Care Office Intervention Incorporating Meal Replacements with individual Physician and Nurse Visits: Subject patients had bi-weekly visits with a primary care physician or nurse for 26 visits over one year. Visits lasted 10 to 15 minutes. Diet prescription was identical to group two (1,200kcal per day with meal replacements for two of three main meals). At each visit, progress was reviewed, including diet, behavior modification and physical activity habits. Questions regarding LEARN manual were addressed.
Once a subject in group two or three reached goal of 10% loss of body weight, she was advised to use meal replacement for only one meal per day. If weight was regained, she was instructed to re-initiate the two-meal replacement per day plan until she lost the re-gained weight.

Statistical Analysis

Primary dependent variable, weight change, was examined by one-way analysis of variance, with subsequent a priori analysis using contrasts for completers and for all subjects by intent to treat (last observation carried forward). Secondary dependent variables, percentage of weight loss from initial body weight, total cholesterol level of 220mg per dL or greater and systolic/diastolic blood pressure of 140/90mm Hg or greater were recoded into dichotomous variables (collapsing across the three intervention conditions). The mean differences for these variables were assessed with independent T-tests. The SPSS statistical package (version seven) was used to analyze the data for statistical significance.

Data Collection Summary:

Timing of Measurements

Baseline and one year for study purposes.

Dependent Variables

Variable One: Weight, measured to the nearest 0.1kg, using a calibrated balance beam scale, subjects wearing light clothes, no shoes
Variable Two: Body Mass Index, height was measured using a wall mounted stadiometer; BMI was calculated.

Variables Two through 12 are analyzed for statistical correlation to change in percentage decrease in body weight (0-5%; 5-10% and >10%)

Variable Three: Waist circumference, measured at the narrowest point of the torso, to the nearest 0.5cm, using a non-stretchable tape measure
Variable Four: Percentage of body fat, calculated from skin folds (triceps, thigh and superior iliac crest were measured to the nearest 0.1mm) using a Lange caliper
Variable Five: Resting energy expenditure, estimated from a 20-minute respiratory sample in fasting subjects, using a ventilated canopy hood by indirect calorimetry
Variable Six: Blood pressure, measured on the right arm using a mercury-column manometer to the nearest millimeter of mercury after the fasting subject had been seated quietly for five minutes
Variable Seven: Total cholesterol, all blood tests were done with the subjects fasted, using standard methods at a statewide certified clinical laboratory
Variable Eight: LDL cholesterol
Variable Nine: HDL cholesterol
Variable 10: Triglycerides
Variable 11: Glucose
Variable 12: Insulin.

Control Variables

All other variables correlation to percentage of weight loss.

Description of Actual Data Sample:

Initial N: 113 females
Attrition (final N): 74 (35% attrition)
Age: 25 to 50 years old; average age 41.4±4.7 years
Ethnicity: Not given
Other relevant demographics: N/A
Anthropometrics: Groups were similar for all measurements (no significant differences for any baseline measurement)
Location: University of Nevada School of Medicine, Reno, Nevada; Nutrition Education and Research program and Department of Internal Medicine.

Summary of Results:

Variables	Group One: Traditional Dietitian Led Intervention Group N=23	Group Two: Traditional Dietitian Led Intervention Group Incorporating Meal Replacements N=26	Group Three: Primary Care Office Intervention Incorporating Meal Replacements with Individual Physician and Nurse Visits N=25	Statistical Significance of Between-Group Differences
Weight Lost (kilograms)	-3.4±5.4	-7.7±7.8	-3.5±5.5	Group 2 > Groups 1 and 3 P=0.03
Weight Lost (percentage)	-4.1±6.4	-9.1±8.9	-4.3±6.5	Group 2 > Groups 1 and 3 P=0.03
Body Mass Index Change	-1.0±2.0	-2.5±2.7	-1.3±2.0	Group 2 > Group 1 P=0.02

Change In Risks Between Baseline and Year One by Percentage Weight Loss

Variable	0% to 5% N=20	5% to 10% N=22	10% or More N=17	Statistical Significance of Correlation Between Percentage of Weight Loss and Variable
BMI	-0.52±0.73	-2.1±0.76	-4.7±2.0	P≤0.05 for any percentage weight loss
Body Fat Percentage	-2.0±4.5	-3.3±4.1	-9.7±4.0	P≤0.05 for any percentage weight loss
Waist Circumference, cm	-1.6±2.4	-4.9±3.6	14.8±4.9	P≤0.05 for any percentage weight loss
Resting Energy Expenditure, kcal per 24 hours	-44±172	-158±102	-211±194	P≤0.05 for weight loss ≥5%
Systolic Blood Pressure, mmHg	2±7	-6±15	-11±13	P≤0.05 for weight loss ≥10%
Diastolic Blood Pressure, mmHg	1±7	-2±9	-4±6	P≤0.05 for weight loss ≥10%
Glucose, mg/dL	3.4±6.3	0.4±7.2	-0.5±8.5	P≤0.01 for weight loss <5%
Insulin, µIU/dL	-0.07±0.78	-0.68±0.65	-0.65±0.95	P≤0.05 for weight loss 5-10% and P≤0.01 for weight loss ≥10%
Total Cholesterol, mg/dL	2.3±20.8	-20.5±33.6	-21.2±22.8	P≤0.05 for weight loss ≥5%
Triglycerides, mg/dL	6.2±45.1	-4.4±60.2	-29.2±42.5	P≤0.01 for weight loss≥10%
HDL-C, mg/dL	-1.2±7.7	-0.2±8.9	1.5±10.0	NS
LDL-C, mgdL	2.3±18.1	-17.4±26.7	-17±22.0	P≤0.05 for weight loss ≥5%

Findings

Data from sub-groups at high risk for cardiovascular disease based on total cholesterol level or blood pressure were analyzed to determine the associations between one-year changes and weight loss, regardless of intervention group:

Baseline total cholesterol at least 220 (N=25), difference between baseline and one year -24.7mg per dL ±30.9; P=0.001. Cholesterol reduction correlated with mean weight loss of 4.1%±7.3%
Baseline systolic blood pressure at least 140mmHg, difference between baseline and one year was -13.0±16.4mmHg. This reduction in blood pressure corresponded to a mean percentage weight loss of 11.0%±9.8%.

Author Conclusion:

Effective approaches are needed for changes in weight loss to reduce the risks of morbidity and mortality. This study demonstrates that weight loss can be achieved using lifestyle counseling which incorporates meal replacement strategies. For the physician, lifestyle counseling with meal replacement provides a useful tool that allows easy explanation and has demonstrated efficacy with patients. Although carried out in a university outpatient setting, this study was designed to evaluate a meal replacement paradigm in the typical busy physician's office practice. Family practitioners should undertake a similar program to deal with overweight and obese patients in their practice. In addition, meal replacements can improve the magnitude of weight loss in a traditional dietitian-led group intervention that includes multiple sessions to promote changes in food selection, suggestions for increasing physical activity and appropriate behavior changes.

Funding Source:

Reviewer Comments:

This was a well-controlled study which looked at three different weight loss intervention strategies. All three strategies resulted in significant weight loss, maintained at one year; but Group Two (the traditional dietitian led group education plus meal replacements) resulted in a much greater weight loss than either of the other groups. The author emphasizes that the physician or nurse brief counseling sessions were successful and could be incorporated into private practices; however, subjects in this intervention group each had bi-weekly appointments over the year. At each appointment, each subject spent 10 to 15 minutes reviewing weight loss strategies, concerns and workbook assignments (2/3 of the visits were with the physician and 1/3 with a nurse). It seems less efficient and more costly to have each individual seen privately for 26 visits over a year than to have them attend a group class 26 times over the year. Additionally, many physicians and nurses do not have the nutrition knowledge, or knowledge of weight management strategies to provide this level of weight management education.

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?		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?	Yes
	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.)	???
	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?	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)?	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