MNT: RDN in Medical Team (2015)


Maruyama C, Kimura M, Okumura H, Hayashi K, Arao T. Effect of a worksite-based intervention program on metabolic parameters in middle-aged male white-collar workers: A randomized controlled trial. Prev Med. 2010; 51: 11-17.

PubMed ID: 20403374
Study Design:
Randomized Controlled Trial
A - Click here for explanation of classification scheme.
Quality Rating:
Positive POSITIVE: See Quality Criteria Checklist below.
Research Purpose:

To investigate the effectiveness of a worksite-based Life Style Modification Program for Physical Activity and Nutrition (LiSM10!) on metabolic parameters in middle-aged male Japanese white-collar workers requiring health guidance based on regular check-up results.

Inclusion Criteria:
  • Male office workers belonging to the health insurance association of the Nichirei Group Corporation in Tokyo and its surrounding area
  • Aged 30 to 59 years
  • Those with metabolic syndrome risk factors based on the results of regular health check-ups. A subject was considered to be at risk of developing metabolic syndrome if one or more abnormalities involving serum lipids, glucose levels and blood pressure were present, with visceral obesity (umbilical circumference of 85cm or more) and BMI higher than 25kg/m2.
  • Considered to be abnormal:
    • Triglyceride (TG) more than 150mg per dL and HDL-cholesterol (HDL-C) less than 40mg per dL
    • Systolic blood pressure higher than 130mm Hg and diastolic blood pressure higher than 85mm Hg
    • Fasting glucose higher than 110mg per dL and HbA1c higher than 5.5%.
Exclusion Criteria:
  • Subjects receiving medical treatments
  • Subjects with a lipoprotein lipase deficiency and abnormal apoE due to hyperlipidemia type III and V.
Description of Study Protocol:


Subjects were recruited from among office workers belonging to the health insurance association of the Nichirei Group Corporation in Tokyo and its surrounding area. Recruitment methods were not described.


Randomized controlled trial; first period of a randomized crossover trial. A randomization code with equal numbers of alternative groups was generated from a list of all participants.

Blinding Used

Implied with measurements, medical check-ups were conducted by the Tokyo Health Service Association, which was not involved in the study.


  • The LiSM10! group attended individualized assessment and collaborative goal-setting sessions based on food group intake and physical activity, followed by two individual counseling sessions with a registered dietitian (20 minutes) and physical trainer (10 minutes) and received monthly website advice during the four-month period from December 2006 to May 2007. They were encouraged to enter current targeted food intakes and pedometer data on self-monitoring websites during the entire study period.
  • The control group received no treatment.

Statistical Analysis

  • Sample size calculated to detect the intervention effect of a 10% change within the group and between groups resulted in a requirement of 45 subjects in each group
  • Between-group comparisons at baseline were made using the Mann-Whitney U test for continuous data and Chi-squared test for proportional data
  • The difference from baseline until the end of the study period for each group was examined using the paired T-test
  • The difference in the program's effectiveness was examined as an inter-group difference in intra-group change, using repeated-measures ANOVA.
Data Collection Summary:

Timing of Measurements

Data from regular health check-ups conducted in December 2006 and May 2007 were used as baseline and post-completion data, respectively.

Dependent Variables

  • Food group intake
  • Number of steps based on pedometer use
  • Anthropometrics measured:
    • BMI
    • Umbilical circumference
    • Blood pressure
  • Biochemical parameters were assessed through standard laboratory methods from fasting blood samples.

Independent Variables

Randomization to LiSM10! program or control group.


Description of Actual Data Sample:
  • Initial N: 115 males enrolled and 101 males were randomized; 49 into no-treatment control, 52 in the LiSM10! intervention
  • Attrition (final N): 87 completed; 48 in the intervention group and 39 in the control group
  • Age: Aged 30 to 59 years; mean age 35.5 years in the control group, 43.1 years in the intervention group
  • Ethnicity: Japanese
  • Other relevant demographics: White-collar workers
  • Anthropometrics: Baseline clinical characteristics were similar between groups, as well as habitual food intake scores, number of steps per day and mean values of self-efficacy for practicing healthy dietary and exercise habits at baseline
  • Location: Tokyo, Japan.


Summary of Results:

Key Findings

  • Habitual food group intakes changed significantly in the LiSM10! group, showing improvements in 14 anthropometric and biochemical parameters contributing to inter-group differences in body weight, body mass index, fasting plasma glucose, insulin and homeostasis model assessment of insulin resistance changes (P<0.01)
  • Increased consumption of food group A (fish, soybeans/soybean-products, green/deep yellow vegetables, white vegetables and mushrooms/seaweed/konnyaku) and decreased consumption of food group B (rice/bread/noodles, confectionaries, sweet drinks, fatty meats, meat products, butter/margarine/dressing/mayonnaise, eggs/liver, fried dishes, pickles, soup and alcoholic drinks) were observed in the LiSM10! group (P=0.00) but not the control group
  • Changes in numbers of steps did not differ between the groups
  • Mean inter-group differences in changes were significant for:
    • Body weight (P<0.05)
    • BMI (P<0.05)
    • AST (P<0.05)
    • Plasma glucose (P<0.05)
    • Insulin (P<0.05)
    • HOMA-IR (P=0.00)
  • The LiSM10! group included a significantly higher percentage of subjects who showed improvements in clinical parameters, achieving BMI and HOMA-IR (P<0.05) within normal ranges, as compared to the control group
  • While changes in the numbers of steps per day did not differ between groups, habitual food group intakes changed significantly in the LiSM10! group, resulting in significant inter-group differences in:
    • body weight (-2.14±2.68 versus -0.80±2.2 kg, -1.29 kg difference, P<0.05)
    • body mass index (-0.74±0.94 versus -0.26±0.69 kg/m2, -0.47 kg/m2 difference, P<0.05)
    • fasting plasma glucose (-1.6±9.6 versus +3.2±10.8 mg/dL, -5.2 mg/dL difference, P<0.05)
    • fasting insulin (-3.73±9.72 versus +0.03±5.96 μU/L, -2.09 μU/L difference, P<0.05)
    • hemoglobin A1C (0.15±0.21 versus 0.07±0.15%, -0.09% difference, P<0.05)
    • HOMA-IR (-1.04±3.04 versus +0.09±1.72, -0.71 difference, P=0.00).
  • There were no differences in triglycerides, HDL-cholesterol or blood pressure between groups.  Renal outcomes were not reported.
Author Conclusion:

Participation in the LiSM10! program, an individually tailored behavior change-oriented program, in the workplace can result in significant improvements in metabolic parameters relating to insulin resistance in middle-aged male white-collar workers. Generalized and relatively simple lifestyle changes are encouraged by a counselor and appear to be useful for preventing metabolic disorders. Further refinement of both personal contact and interactive technology-based interventions is necessary to confirm long-term effects.

Funding Source:
Meiji Dairies Corporation, Suntory Holdings Ltd, Nichirei Foods Inc.
Food Company:
University/Hospital: International Life Sciences Institute, Japan
Reviewer Comments:
  • Large number of dropouts from no-treatment control group; authors mention needing 45 subjects per group for adequate power and only 39 subjects in the control group were included in the analysis
  • Authors note that the major limitation of the study was the low completion rate of self-reports, with only 75% of subjects in the LiSM10! and 50% of subjects in the control group returning useable records. In the control group, post-data collection completion rates were lower than those 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? 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%.) Yes
  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? Yes
  5.1. In intervention study, were subjects, clinicians/practitioners, and investigators blinded to treatment group, as appropriate? N/A
  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? N/A
  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? ???
  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? ???
  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)? No
  8.5. Were adequate adjustments made for effects of confounding factors that might have affected the outcomes (e.g., multivariate analyses)? ???
  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