EAL

PDM: Metabolic Syndrome (2013)

Citation:

Lee K, Lee J, Bae WK, Choi JK, Kim HJ, Cho B. Efficacy of low-calorie, partial meal replacement diet plans on weight and abdominal fat in obese subjects with metabolic syndrome: A double-blind, randomized controlled trial of two diet plans - one high in protein and one nutritionally balanced. Int J Clin Pract. 2009; 63(2): 195-201.

PubMed ID: 19196357

Study Design:

Randomized Controlled Trial

Class:

A - Click here for explanation of classification scheme.

Quality Rating:

POSITIVE: See Quality Criteria Checklist below.

Research Purpose:

To evaluate the efficacy of two low-calorie diets with partial meal replacement plans [a high-protein plan (HP) and a nutritionally balanced conventional (C) plan] on reducing obesity in obese subjects with metabolic syndrome.

Inclusion Criteria:

No mental or physical disorder
Diagnosed metabolic syndrome based on ATPIII definition; BMI 25kg/m² or more; waist circumference of 90cm or more for men or 80cm or more for women, serum triglyceride 150mg per dL or more and having at least one of the following signs:
- High-density lipoprotein (HDL) of 40mg per /dL for men or less than 50mg per dL for women
- Fasting blood sugar 100mg per dL or more
- Systolic blood pressure 130mm Hg or more or diastolic blood pressure 85mm Hg or more.

Exclusion Criteria:

Pregnancy and lactation
Anorexia nervosa
Unstable medical illness
Clinical significant abnormal laboratory results
Concurrent use of antiobesity agents (on a regular basis within three months of study entry), antidepressants, antipsychotics, antiepileptics, thyroid hormones, antithyroid drugs, antiarrhythmics or systemic steroids
History of gastrointestinal tract surgery or very low calorie diet (with the aim of losing weight) within the past six months
Experiencing a hypersensitive reaction to certain foods or medications.

Description of Study Protocol:

Recruitment

Volunteers were recruited from the Health Promotion Center or Ambulatory Clinic for Family Practice in Seoul National University Hospital from April 2006 to February 2007.

Design

Randomized controlled trial
In a 12-week, double-blind study, randomized 75 participants to either the HP- or the C-plan group. Recorded key metrics at zero and 12 weeks:
- HP-plan group (30% of energy from protein, 50% from carbohydrates, 20% from lipids and 25g of daily dietary fiber) or the C-plan group (15% energy from protein, 65% from carbohydrates, 20% from fat and 25g daily dietary fiber)
- Visits: Baseline, one, two,four, eight and 12 weeks
- A clinical dietitian provided nutritional and lifestyle counseling
- Brief counseling by a nurse was provided to promote increased physical activity and reduce sedentary behavior
- Blood and urine samples for tested for metabolic disorders and cardiovascular risk factors
- Visceral fat area, body fat mass and body fat ratio were measured
- Smoking history, alcohol consumption, exercise habits, medication usage and educational and socio-economic status from a self-reported questionnaire and information about height, weight, waist circumference and systolic and diastolic blood pressure
- Serum concentrations of cholesterol, triglycerides, insulin, glucose and uric acid
- Electrocardiograms, chest X-rays
- Insulin resistance by homeostasis model assessment
- 24-hour urine collections for calcium nitrogen and creatinine concentration
- Three-day recall food diary at the beginning and at the end of the study
- Whole body fat mass and truncal fat mass with dual energy X-ray absorptiometry and body fat ratio by bioelectrical impedance analysis.

Blinding Used

Implied with measurements.

Intervention

Counseling:

HP-plan group: 30% of energy from protein, 50% from carbohydrates, 20% from lipids and 25g of daily dietary fiber
C-plan group: 15% energy from protein, 65% from carbohydrates, 20% from fat and 25g daily dietary fiber.

Statistical Analysis

Pearson and Mann-Whitney tests were used for evaluating group differences in basic characteristics. Differences in total calorie intake, nutrient intake, metabolic and cardiovascular abnormalities, whole body and truncal fat mass and the abdominal fullness index.
ANOVA to analyze between group differences in changes of body weight, BMI, waist circumference, body fat ratio and blood pressure and the Wilcoxon rank sum test to analyze with-group differences in whole body and truncal fat mass. Mean and SD were calculated.

Data Collection Summary:

Timing of Measurements

Visits: Baseline, one, two, four, eight and 12 weeks.

Dependent Variables

Blood and urine samples for tested for metabolic disorders and cardiovascular risk factors
Visceral fat area, body fat mass and body fat ratio were measured
Serum concentrations of cholesterol, triglycerides, insulin, glucose and uric acid
Electrocardiograms, chest X-rays
Insulin resistance by homeostasis model assessment
24-hour urine collections for calcium nitrogen and creatinine concentration
Three-day recall food diary at the beginning and at the end of the study
Whole body fat mass and truncal fat mass with dual energy X-ray absorptiometry and body fat ratio by bioelectrical impedance analysis.

Independent Variables

HP-plan group (30% of energy from protein, 50% from carbohydrates, 20% from lipids and 25g of daily dietary fiber) or the C-plan group (15% energy from protein, 65% from carbohydrates, 20% from fat and 25g daily dietary fiber)
A clinical dietitian provided nutritional and lifestyle counseling
Brief counseling by a nurse was provided to promote increased physical activity and reduce sedentary behavior.

Control Variables

Smoking history, alcohol consumption, exercise habits, medication usage and educational and socio-economic status from a self-reported questionnaire and information about height, weight, waist circumference and systolic and diastolic blood pressure.

Description of Actual Data Sample:

Initial N: N=80
Attrition (final N): N=75
- HP plan group: N=37 (17 men, 20 females)
- C-plan group: N=38 (19 men, 19 females)
Age:
- HP plan group: 47.0±12.6 years
- C plan group: 49.0±11.2 years
Ethnicity: Assumed Korean
Anthropometrics: Groups did not differ significantly in gender ratio or baseline characteristics or in smoking history, alcohol intake, exercise habits, economic status or education level
Location: Seoul.

Summary of Results:

Key Findings

The overall mean weight loss was 5kg in the HP-plan group and 4.9kg in the C-plan group (P=0.72)
Truncal fat mass decreased 1.6kg in the HP-plan group (P<0.05) and 1.5kg in the C-plan group (P<0.05), while whole body fat mass decreased 2.5kg in the HP-plan group (P<0.05) and 2.3kg in the C-plan group (P< 0.05)
Between-group losses did not differ significantly for truncal (P=0.52) or whole body (P=0.77) fat mass. Among subjects with 70% or more dietary compliance, however, truncal and whole body fat mass decreased more in the HP-plan group (Delta 2.2kg and Delta 3.5kg, respectively) than in the C-plan group (Delta 1.3kg and Delta 2.3kg [corrected], respectively) (P<0.05).
Two groups did not differ significantly in their intake of total energy, macronutrients, calcium or fiber, but at 12 weeks the protein intake was significantly higher and the carbohydrate intake significantly lower in the HP-plan group
At 12 weeks, the overall mean weight loss, as well as mean losses in body weight, BMI, waist circumference, truncal fat mass, whole body fat mass and lean body mass was statistically significant for both groups
Serum triglycerides and insulin levels significantly decreased and serum HDL-C levels were significantly increased in both groups. No significant differences were observed between groups.
The two groups did not differ in calcium excretion
Both partial meal replacement plans were tolerated and no serious adverse events were observed.

Author Conclusion:

The HP and C plans had a similar effect on weight and abdominal fat reduction, but the HP plan was more effective in reducing body fat among compliant subjects. There is a need for further study of the efficacy of diets with a high proportion of protein and better compliance on reducing abdominal fat.

Funding Source:

Industry:

Herbalife

Pharmaceutical/Dietary Supplement Company:

Reviewer Comments:

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?	???
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?		Yes
	5.1.	In intervention study, were subjects, clinicians/practitioners, and investigators blinded to treatment group, as appropriate?	Yes
	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?	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?	Yes
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