MNT: Weight Management (2015)

Lee IS, Shin G, Choue R. A 12-week regimen of caloric restriction improves levels of adipokine and pro-inflammatory cytokines in Korean women with BMIs greater than 23 kg/m2. Inflammation Research, 2010; 59: 399-405. PubMed ID: 19916070
Study Design:
Before-After Study
D - Click here for explanation of classification scheme.
Quality Rating:
Positive POSITIVE: See Quality Criteria Checklist below.
Research Purpose:
  • To evaluate the blood levels of adipokines and pro-inflammatory cytokines after weight reduction via the restriction of calorie consumption
  • Also, to investigate the effects of weight reduction on blood levels of lipids, glucose, insulin and high-sensitivity C-reactive protein (hs-CRP) in Korean women with body mass indices (BMI) higher than 23kg/m2.
Inclusion Criteria:
  • Healthy volunteers recruited at Kyung Hee University Hospital in Seoul, Korea, between April 2007 and October 2007
  • BMI over 23kg/m2
  • Regular menstrual cycles
  • Aged between 21 and 50 years
  • Signed informed consent.
Exclusion Criteria:
  • Presence of any serious disease, recent surgery or eating disorder
  • Hormonal contraceptives or any other drug taken during the previous three months.
Description of Study Protocol:


Recruited from Kyung Hee University Hospital.


  • 46 subjects were assigned to participate in study
  • During the study, a Registered Dietitian instructed all participants five times to reduce their caloric consumption and to increased physical activity: Steps included recommendations for a 500-calorie reduction in daily intake to each woman on the basis of three-day food records, assessment of average daily intake of calories and nutrients by using CAN pro version 3.0, individual guidance on increasing physical activity and monitoring of physical activity of each subject
  • Anthropometric assessments were completed and blood levels of lipids, adipokines and pro-inflammatory cytokines were analyzed at the beginning and end of the experiment.

Blinding Used



Calorie restriction.

Statistical Analysis 

  • Results expressed as means ±standard deviations
  • Statistical significance defined as P<0.05, P<0.01 and P<0.001
  • Paired T-tests used to compare the changes in anthropometrics, dietary intake and levels of lipids, adipokines and pro-inflammatory cytokines from baseline values.
Data Collection Summary:

Timing of Measurements

Measurements taken at baseline and after caloric restriction
  • Anthropometric measurements including body weight and height measured using X-Scan plus; waist circumference measured using flexible steel metric tape
  • Body fat mass, fat-free mass and visceral and subcutaneous fat mass measured using X-Scan Plus
  • Daily intake of calories, macronutrients and fiber assessed using three-day food records
  • Blood samples were collected after a 12-hour overnight fast; plasma triacylglycerol, total cholesterol, HDL-cholesterol, LDL-cholesterol, high-sensitivity C-reactive protein, plasma glucose concentrations and serum insulin were measured
  • Plasma concentrations of leptin (detection limit of 0.5mcg per L), adiponectin (detection limit of 50ng per L, sensitivity 30pg per ml), visfatin (sensitivity of 100pg per ml) and resistin (sensitivity of 100pg per ml)
  • Plasma concentrations of IL-1 beta, IL-6, IL-8, TNF-a and IFN-y.

 Dependent Variables

  • Body weight (kg)
  • Body mass (kg/m2)
  • Fat-free mass (kg and percentage)
  • Fat mass (kg and percentage)
  • Visceral fat (percentage)
  • Subcutaneous fat (kg)
  • Waist and hip ratio
  • Weight and height
  • Systolic blood pressure (mmHg)
  • Diastolic blood pressure (mmHg)
  • Lipid panel (total lipids, tricylglycerol, total cholesterol, HDL-cholesterol, LDL-cholesterol, TG-to-HDL-cholestero ratio, free fatty acid)
  • Hs-CRP, insulin and glucose levels
  • Plasma levels of adipokines and cytokines
  • Daily intake of calories, macronutrients and fiber.
Independent Variables
Restriction of calorie consumption.
Description of Actual Data Sample:
  • Initial N: 46 females
  • Attrition (final N): 46 females
  • Age: 34.1±11.5 years; range of 21 to 50 years
  • Ethnicity: Korean
  • Other relevant demographics: None
  • Anthropometrics: See "Results" section 
  • Location: Seoul, Korea.


Summary of Results:

Key Findings

  • Calorie restriction
    • Dietary total calorie consumption of subjects decreased significantly from 1,802.4kcal per day to 1,409.1kcal per day after caloric restriction (P<0.05)
    • Average daily intake of carbohydrates, proteins and fats significantly decreased (P<0.05)
    • Average daily fiber consumption did not change.
  • Anthropometrics and body composition: After 12 weeks of caloric restriction, body weight, BMI, fat mass, fat free mass, visceral fat mass, subcutaneous fat mass, waist-hip ratio, waist-height ratio and blood pressure decreased significantly (P<0.05)
  • Blood analysis
    • After caloric restriction, serum total lipid levels, total cholesterol, HDL-cholesterol, LDL cholesterol, hs-CRP, insulin and glucose levels did not change
    • Triacylglycerol and TG-to-LDL-cholesterol ratio significantly decreased (P<0.05) after caloric restriction and concentration of free fatty acids significantly increased (P<0.05) after intervention.
  • Levels of adipokines
    • Concentrations of leptin and visfatin significantly decreased (P<0.05) after intervention
    • Concentrations of adiponectin significantly increased (P<0.001)
    • Plasma concentrations of resistin did not change.
  • Levels of pro-inflammatory cytokines
    • TNF-a and IFN-y levels decreased (P<0.05) while concentrations of IL-1beta, IL-6, and IL-8 did not change
    • Significant positive correlation was found between fat mass reduction and changes in leptin levels (P<0.05)
    • No correlation found between fat mass reduction and changes of other adipokines.



After Caloric Restriction

Statistical Significance of Group Difference

Body Weight (kg)




Body Mass Index (kg/m2)




Fat-Free Mass (kg)




Fat-Free Mass (%) 66.6±0.5 68.4±0.6 P<0.001
Fat Mass (kg) 23±0.8 20.7±0.8 P<0.001
Fat Mass (%) 33.4±0.5 31.6±0.6 P<0.001
Visceral Fat (kg) 2.7±0.2 2.3±0.1 P<0.05
Subcutaneous Fat (kg) 20±0.7 18.2±0.7 P<0.001
Waist/Hip 0.87±0.01 0.85±0.01 P<0.001
Waist/Height 0.53±0.01 0.52±0.01 P<0.05
Systolic Blood Pressure (mmHg) 120.2+2 114.3+2.1 P<0.01
Diastolic Blood Pressure (mmHg) 73.5±1.6 69±1.7 P<0.01
Total Lipids (mg/dL) 554.6±19.5 522.6±16.1  
Triacylglycerol (mg/dL) 99.8±9.2 87.9±8.8 P<0.05
Total Cholesterol (mg/dL) 193.3±5.4 189.4±5  
HDL-Cholesterol (mg/dL) 57.2±2 55.9±1.7  
LDL-Cholesterol (mg/dL) 115.9±5 118.2±4.7  
TG/HDL-Cholesterol Ratio 2.01±0.31 1.68±0.19 P<0.05
Free Fatty Acids (mcEq/L) 551±40.1 663.5±45 P<0.05
Hs-CRP (mg/L) 0.13±0.02 0.1±0.02  
Insulin (mcIU/ml) 11.1±0.7 11.4±0.6  
Glucose (mg/dL) 85.8±1.3 85.6±1.3  
Leptin (mcg/ml) 10.3±0.6 9±0.7 P<0.05
Adiponectin (mcg/ml) 7.8±0.6 11.1±1.1 P<0.001
Leptin/Adiponectin Ratio 2.26±0.46 1.07±0.12 P<0.001
Resistin (ng/ml) 3.54±0.29 3.88±0.39  
Visfatin (ng/ml) 0.83±0.1 0.62±0.05 P<0.05
Author Conclusion:
  • Caloric reduction of approximately 500kcal per day led to reduction in body weight and fat mass as well as visceral and subcutaneous fat in Korean women with a BMI over 23kg/m2
  • Additionally, caloric restriction significantly reduced plasma triacylglycerol levels and blood pressure
  • No relationship between physical activity and other factors was observed. 
Funding Source:
Other: Not described
Reviewer Comments:
Small sample size and many of the subjects had normal clinical characteristics at baseline. 
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? 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? 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? 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? 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? 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)? Yes
  8.5. Were adequate adjustments made for effects of confounding factors that might have affected the outcomes (e.g., multivariate analyses)? No
  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? No
  10.2. Was the study free from apparent conflict of interest? Yes