EAL

UM: Role of Umami in the Regulation of Energy Intake (2014)

Citation:

Study Design:

Class:

- Click here for explanation of classification scheme.

Quality Rating:

Research Purpose:

To investigate whether the addition of some MSG to target foods is likely to increase appetite and improve nutrition in institutionalized elderly persons.

Inclusion Criteria:

Institutionalized patients who physicians thought would benefit from the intervention.

Exclusion Criteria:

A sodium-restricted diet.

Description of Study Protocol:

Recruitment

Physicians in charge of the wards selected a sample of subjects.

Design

Non-randomized controlled trial
Six blocks of two tests, one of Menu A, the other of Menu B
For the first three blocks, Menu A was presented without added MSG while Menu B was served with 0.6% MSG added to target foods
For the last three blocks, Menu B was offered without MSG and Menu A with 0.8% added to target foods.

Blinding Used

Subjects were told that there would be a six-month study with the aim of improving he quality of meals.

Intervention

No MSG
MSG: Addition of 0.6% MSG to soup and vegetable; the dosage used was previously determined using young adults.

Statistical Analysis

Analysis of variance
Description of statistics was very poor.

Data Collection Summary:

Timing of Measurements

Before and after meals containing target foods.

Dependent Variables

Food intake: Weighing food and analyzing nutrients using a computerized food composition table.

Independent Variables

The menus with target foods (soup and vegetable) with and without 0.6% MSG were presented on six occasions each. Six blocks of two tests, with one using Menu A and the other of Menu B. For the first three blocks, Menu A was presented without added MSG while Menu B was served with 0.6% MSG added to target foods (soup and vegetable). For the last three blocks, Menu B was offered without MSG and Menu A with 0.8% added to target foods.

Control Variables

Test meals were on the same day of the week with a two-week interval between successive tests. Within blocks, the order of presentation of the menus was random.

Description of Actual Data Sample:

Initial N: A total of 100
Attrition (final N): A total of 65; 35 patients died or had to be excluded for various reasons (loss of autonomy, illnesses, change of residences, etc.)
Age: Age was 84 years
Location: Paris.

Summary of Results:

Findings

For Menu A (N=46):
- The intake of individual foods was not significantly different depending on the presence or absence of MSG
- Significant main effects of weeks appeared for bread, soup and veal intake [F(2, 90) = 3.9, 5.8 and 6, respectively]; Intake generally decreased over repeated presentations
- When MSG was present, increased intakes of calcium, F(1, 45) = 4.5, P<0.05 and magnesium, F(1, 45) = 5.2, P<0.05, were noted
- Significant interactions of MSG level times weeks were observed for calories, F(2, 90) = 3.2 P<0.05 and magnesium, F(2, 90) = 3.7 P<0.05, intake indicating different changes in intake over weeks, depending on MSG conditions
- Caloric and magnesium intake decreased over weeks when no MSG was added, while they did not when MSG was present
- Significant main effects of Weeks were observed for intakes of protein (P<0.05), fats (P<0.02), cholesterol (P<0.02) and sodium (P<0.01), showing a large degree of variability independent of MSG treatment.
For Menu B:
- The intake was affected by the presence of MSG; more soup and mashed potatoes (P<0.05) and less soft white cheese was consumed on MSG weeks
- A MSG times Week interaction was noted for soup intake (P<0.05); the sharp fall in intake observed after Week in the No MSG was replicated in the 0.6% MSG condition
- More calories (P<0.05), fats (P<0.05) and sodium (P<0.01) were ingested under the 0.6% MSG condition
- Significant main effects of Weeks were seen for soup, soft white cheese and canned fruits intakes and for sodium content of the meals.

Author Conclusion:

MSG can act as a palatability enhancer in the context of the French diet. It can facilitate long-term intake in both young and elderly persons but it should be utilized cautiously so as to improve nutrition.

Funding Source:

Other:

not reported

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?		???
	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?	???
	2.3.	Were health, demographics, and other characteristics of subjects described?	No
	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?	???
	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?	???
	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.)	No
	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?	???
	7.6.	Were other factors accounted for (measured) that could affect outcomes?	No
	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?	No
	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)?	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?	Yes
	10.2.	Was the study free from apparent conflict of interest?	Yes