AWM: Eating Frequency and Patterns (2013)

Study Design:
- Click here for explanation of classification scheme.
Quality Rating:
Research Purpose:
To examine breakfast consumption patterns of the U.S. adult population using the USDA Nationwide Food Consumption Survey, focusing on comparisons of 11 dietary component intakes.
Inclusion Criteria:
Adults aged 18 - 49 years from conterminous states.
Exclusion Criteria:
Not mentioned.
Description of Study Protocol:


During each of 4 quarters for April 1977 through March 1978 data were collected from 48 conterminous states by using a random probability, multi-stage, stratified sampling design. 


Cross-sectional study.  The sample was partitioned by 6 age/sex classes and by 4 breakfast consumption patterns:  males & females 18 - 24 years, males & females 25 - 34 years, and males & females 35 - 49 years.

Blinding used (if applicable)

Not applicable.

Intervention (if applicable)

1977-1978 USDA Nationwide Food Consumption Survey.

Statistical Analysis

Most popular breakfasts for each of 6 classes were estimated by summing the number of times a specified type of breakfast was consumed during the 3 days, dividing by total number of breakfasts consumed and expressed as a percentage.  Each of 6 classes were partitioned into 4 groups based on breakfast consumption patterns.  Percentages of breakfasts skipped were were calculated for each of 4 groups within each of 6 classes.  General linear model and Duncan's multiple-range test were used to test for significant differences in mean dietary component intake levels of the 4 groups of individuals within each of the 6 age/sex classes.

Data Collection Summary:

Timing of Measurements

Dietary records from the USDA 1977-78 Nationwide Food Consumption Survey used.

Dependent Variables

  • Intakes of 11 dietary components calculated from intake data using MSU Nutrient Data Bank.  Nutrients include:  fat, sugar, cholesterol, sodium, vitamin A, pyridoxine, iron, calcium, magnesium, copper, zinc.  

Independent Variables

  • Food intake info obtained by 3 day food records.  Trained interviewers inquired about the kinds and amounts of all foods and beverages consumed on day preceding interview.  Individuals then recorded foods and beverages consumed the day of and the day following the interview.

Control Variables


Description of Actual Data Sample:

Initial N: 15,959 individuals with complete 3 day food records.

Attrition (final N):  See above.

Age:  Males 18 - 24 years (n=1904), females 18 - 24 years (n=2366), males 25 - 34 years (n=2343), females 25 - 34 years (n=3303), males 35 - 49 years (n=2506), females 35 - 49 years (n=3537). 

Ethnicity: Not mentioned.

Other relevant demographics: Not mentioned.

Anthropometrics:  Not mentioned.

Location:  United States


Summary of Results:

Other Findings

Results indicated that approximately 1/4 of the adult population skipped breakfast regularly.  Males age 25 - 34 years had the highest percentage of skipped breakfasts (31.5%), followed by females age 18 - 24 (30.9%), females age 25 - 34 (29.1%), males age 18 - 24 (28.7%), males age 35 - 49 (26.7%) and females age 35 - 49 (23.7%).

For those adults who consumed breakfast, the 4 most commonly consumed breakfasts were eggs, bread and coffee; ready-to-eat cereal with milk; coffee and bread; and eggs, bread and milk.

Assessments of average intakes of showed that omission of the breakfast meal had a significant negative impact, particularly among adult females, on the diet quality for iron, calcium, pridoxine, zinc, magnesium, and copper.

Findings indicated that for all age/sex classes, consumption of ready-to-eat cereal at breakfast, whether frequently or on a more limited basis, increased the average daily intake levels of the underconsumed nutrients.

Groups of adults who regularly consumed ready-to-eat cereal at breakfast had, on average, lower average daily intakes of fat and cholesterol.

Adult females who skipped breakfast regularly, and to a lesser extent those who did not consume ready-to-eat cereal at breakfast, consumed somewhat less nutritious foods and/or less food throughout the entire day.  On the other hand, adult males who regularly skipped breakfast, especially those aged 35 - 49 years, tended to consumed more foods, and perhaps more nutritious foods, during the remainder of the day than those males who regularly consumed breakfast.


Author Conclusion:
It is apparent from these results that the omission of breakfast, particularly by adult females, was a strong factor contributing to dietary inadequacies.  It is also apparent that adult females who regularly skipped breakfast had less appropriate dietary intake patterns throughout the day, resulting in quite low intake levels of pyridoxine, iron, zinc, copper, calcium, and magnesium.  Adult males who skipped breakfast frequently consumed more food during the remainder of the day.  However, this increased consumption did not counterbalance completely the nutrient inadequacies that resulted from skipping breakfast.  It was concluded that regular breakfast consumption greatly enhanced the overall diet quality of the U.S. adult population.
Funding Source:
University/Hospital: University of Missouri, Michigan State University
Reviewer Comments:
Large sample size.  Weights were used as a means for correcting nonrepresentativeness in the sample population.  Statistics not well defined.
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? Yes
  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.) Yes
  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? N/A
  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? 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? Yes
  6.3. Was the intensity and duration of the intervention or exposure factor sufficient to produce a meaningful effect? N/A
  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? 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? N/A
  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? ???
  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? Yes
  8.3. Were statistics reported with levels of significance and/or confidence intervals? No
  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)? ???
  8.6. Was clinical significance as well as statistical significance reported? No
  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