EAL

DM: Effectiveness of MNT Provided by RD/RDN (2015)

Citation:

Imai S, Matsuda M, Hasegawa G, Fukui M, Obayashi H, Ozasa N, Kajiyama S. A simple meal plan of 'eating vegetables before carbohydrate' was more effective for achieving glycemic control than an exchange-based meal plan in Japanese patients with type 2 diabetes. Asia Pac J Clin Nutr. 2011; 20 (2): 161-168.

PubMed ID: 21669583

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 assess the difference in outcomes between groups given guidance to follow the exchange system or to consume vegetables before carbohydrates at each meal.

Inclusion Criteria:

Type 2 diabetes mellitus according to WHO guidelines
Capable of performing basic self-management skills.

Exclusion Criteria:

Chronic liver disease
Cardiovascular disease
Smoking more than 40 cigarettes per day
Drinking more than 50g of alcohol per day.

Description of Study Protocol:

Recruitment

Subjects were recruited from a diabetes clinic in Kyoto, Japan. Of the 221 subjects screened, 148 were approved to enroll in the study and of those, 101 agreed to participate. Twice as many subjects were randomized to the Experimental Group.

Design

Randomized controlled trial
Study subjects were randomized to either receive education to consume vegetables prior to carbohydrates at the meal (study group, VBC) or to use the exchange system (control group, EXB)
Subjects were enrolled for 24 months and were followed monthly to receive education from the dietitian.

Blinding Used
Implied with measurements.

Intervention

The Experiment Group (VBC) was instructed to eat vegetables first and carbohydrates last at each meal. They were instructed to consume green vegetables at least once daily, not fruits and to chew each bite more than 20 times. The education focused on low-GI vegetables such as mushrooms and seaweed.
The Control Group (EXB) was instructed on the exchange based system and portion size. They were recommended to consume more than 350g of vegetables and 80 calories of fruits each day. Education took approximately 60 minutes at the initial visit and 40 minutes at each subsequent visit.

Statistical Analysis

Student's T-test was used to test differences between the two study groups
Paired T-tests were performed to analyze within-group changes over time
Chi-square tests were used to compare categorical data
Repeated measures ANOVA was performed for comparisons among time and the two study groups (baseline, 12-month, 24-month)
Spearman's correlation coefficients were calculated to investigate the association among dietary intakes and HbA1c, BMI and serum lipid levels
P<0.05
Measurements were analyzed using SPSS 15.0 for Windows.

Data Collection Summary:

Timing of Measurements

Laboratory data, body weight and calculated BMI were collected at baseline and monthly for the duration of the study period
Dietary intake was assessed at the beginning of the study and over seven days after two months of intervention
Physical activity was assessed prior to beginning of study and for 21 days after intervention
Dietary restraint and overeating tendencies were measured at the initial visit and after two months of the intervention.

Dependent Variables

Hemoglobin A1c: Determined by latex cohesion method
Weight: To the nearest 100g while wearing minimal clothing and no shoes
Height: Measured without shoes
BMI: Calculated
Total cholesterol: Enzyme assay
Triglyceride level: Enzyme assay
HDL-cholesterol: Direct method
LDL-cholesterol: Enzymatic assay.

Independent Variables

Vegetables before carbohydrate (Experimental Group) as compared to exchange method (Control Group).

Dietary intake was assessed by food records collected over three days
Physical activity was assessed using Kens Activity Monitor Life Corders for seven days
Dietary restraint and overeating tendencies were measured using the Dutch Eating Behavior Questionnaire.

Description of Actual Data Sample:

Initial N: 101 (48 males, 53 females)
Attrition: 92 completed the 24-month follow-up (65 in the VBC Group and 27 in the EXB Group)
Age: Mean, 63.4 years in the VBC Group and 65.1 years in the EXB Group
Ethnicity: Not discussed
Anthropometrics: Groups were statistically equivalent for BMI, duration of DM diagnosis, blood pressure, A1C, cholesterol and DM treatment at baseline
Location: Kyoto, Japan.

Summary of Results:

Key Findings

Variables		Baseline	12-Month	24-Month	Time¹	Time x Group¹
BMI (kg/m²)	VBC	23.7±4.0	23.3 ±4.8	23.6±3.8	0.963	0.320
BMI (kg/m²)	EXB	22.7±4.4	23.7±4.4	22.7±4.3
HbA1c (%)	VBC	8.3±1.7	6.7±0.8***♦	6.8±0.7***♦	<0.001	0.016
HbA1c (%)	EXB	8.2±1.8	7.2±1.1	7.3±1.1*

1: Repeated-measures ANOVA
*P<0.05
***P<0.01
♦P=0.05 VBC vs. EXB Group.

Other Findings

Attrition rate in the Study Group was 6% vs. 16% in the Control Group
Both groups experienced a decrease in consumption of rice, meat, egg, sweets and beverages as well as total calories
Both groups experienced an increase in consumption of green vegetables and fish
Neither BMI, diastolic BP nor serum lipid levels was significantly different between the two groups at 12-months or 24-months of follow-up
There was no significant difference between groups for energy expenditure at baseline and after intervention
Dutch Eating Behavior Questionnaire (DEBQ) demonstrated that external and restrained eating behaviors improved in both groups after intervention
Dietary fiber was higher in VBC Group
BMI was not significantly different within or between groups during the 24 months of follow-up
Significant improvements in HbA1c were observed in both groups (8.3% to 6.8%, P<0.01 in the VBC Group and 8.2% to 7.3%, P<0.05 in the EXB Group), but HbA1c levels were significantly lower in the VBC Group than the EXB Group after six, nine, 12 and 24 months of the study (P=0.016)
While both groups had significant improvements over time in total cholesterol, LDL-cholesterol and blood pressure, there were no significant differences between groups
There were no significant changes within or between groups in terms of HDL-cholesterol and triglycerides.

Author Conclusion:

A simple meal plan consisting of eating "vegetables before carbohydrate" was more effective in achieving glycemic control over a 24-month period than an "exchange-based meal plan" in Japanese patients with diabetes as evidenced by HbA1c at six, nine, 12 and 24 months.

Funding Source:

Government:

Grant-in Aid for Scientific Research from the Ministry of Health. Labor and Welfare project # 19500605

Reviewer Comments:

Past or concurrent DM education not assessed
Compliance with food records not discussed.

As Noted by the Authors

Pros

Study Group had significantly lower attrition rate indicating that intervention was better tolerated than traditional exchange system counseling
Study Group had a significant increase in green vegetable consumption, as compared to EXB.

Cons

Both groups had changes in medications during study period. Some participants increased or changed their medications while other decreased their doses.
Not all participants were newly diagnosed with T2DM and therefore may have education in the past about disease management.

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)	???
	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?	No
	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?	???
	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?	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?		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