MNT: Gastrointestinal Disorders (2015

Lee AR, Ng DL, Dave E, Ciaccio EJ, Green PHR. 2009. The effect of substituting alternative grains in the diet on the nutritional profile of the gluten-free diet. J Hum Nutr Diet, 22, pp. 359-363. doi: 10.1111/j.1365-277X.2009.00970.x PubMed ID: 19519750
Study Design:
Retrospective Cohort Study
B - Click here for explanation of classification scheme.
Quality Rating:
Neutral NEUTRAL: See Quality Criteria Checklist below.
Research Purpose:
To determine whether the nutritional profile of a gluten-free diet could be improved through the use of alternative grains.
Inclusion Criteria:
Not specified by authors.
Exclusion Criteria:
Not specified by authors.
Description of Study Protocol:


50 patients of the Celiac Disease Center were randomly selected to participate in the study.


  • In this retrospective review of diet history, 50 randomly selected patients from the Celiac Disease Center at Columbia University provided the dietitian with a three-day food diary of their usual intakes
  • The grain/starch choices were recorded by grain category, number of servings of grains and meal at which grain was consumed
  • Intake patterns from the 50 food diaries were averaged together to create one average intake pattern
  • The alternative gluten-free diet pattern was created by substituting only the grain or starch portion of the standard menu pattern with alternative gluten-free grains or grain products. This alternative pattern used oats at breakfast, high-fiber brown rice bread at lunch and quinoa as a starch side dish at dinner. The grain choices were then analyzed for nutrient content comparing both the standard and alternative diet pattern.

Statistical Analysis

ANOVA and paired T-tests were used to identify statistical significance between the standard and alternative gluten-free diet patterns.

Data Collection Summary:
  • Timing of measurements: Three-day food diaries were retrospectively reviewed by the dietitian
  • Dependent variables: Three-day food diaries self-reported by patients
  • Independent variables: Substituting the grain or starch portion of the average meal pattern with alternative gluten-free grains (oats at breakfast, high-fiber brown rice bread at lunch and quinoa at dinner)
  • Control variables: Only the grain choices were analyzed for the nutrient content comparing both the standard and alternative diet pattern.
Description of Actual Data Sample:
  • Initial N: 50 patients
  • Attrition (final N): None specified by authors
  • Age: Not specified
  • Ethnicity: Not specified
  • Other relevant demographics: Not specified
  • Anthropometrics: Not specified
  • Location: Celiac Disease Center, Columbia University, New York.
Summary of Results:

Key Findings

  • The standard gluten-free diet did not meet the USDA's recommended six to 11 servings of grains per day
  • Standard gluten-free diet grains consisted of 44% rice (predominately white), 8% potato, 5% oats, 3% corn, 1% Buckwheat and 1% quinoa; 38% consumed no grains; 55% of snacks comprised commmercially prepared snacks (chips, pretzels, GF cookie, donuts and cake)
  • The alternative diet pattern provided an improved nutrient profile compared to the standard gluten-free diet (P=0.0002)
  • The change in dietary grains significantly increased protein (20.6g vs. 11g), iron (18.4mg vs. 1.4mg), calcium (182mg vs. 0.0mg) and fiber (12.7g vs. 5.0g).
Author Conclusion:
  • Changing the grains in a gluten-free diet has the potential to improve the nutritional profile of the diet for individuals with celiac disease
  • Patients and their dietary counselors require education on alternative sources to diversify the standard gluten-free diet.
Funding Source:
University/Hospital: Celiac Disease Center, School of Medicine, Columbia University
Reviewer Comments:
  • Although the authors stated that selected nutrient levels significantly increased with changing the dietary grains (i.e., iron, calcium, fiber and protein), they did not provide a P-value for each nutrient. The only P-value provided was for an overall improved nutrient profile.
  • The authors do state limitations of the study: These include a population bias because the diet history records were provided by individuals attending a large celiac disease center, a small sample size (N=50), limited nutritional analysis and the potential inaccuracies of reported food intakes.
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? No
  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? 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? N/A
  4.1. Were follow-up methods described and the same for all groups? N/A
  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%.) N/A
  4.3. Were all enrolled subjects/patients (in the original sample) accounted for? ???
  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? No
  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.) N/A
  5.3. In cohort study or cross-sectional study, were measurements of outcomes and risk factors blinded? No
  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? N/A
  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? N/A
  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? N/A
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)? N/A
  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