DLM: Trans Fatty Acids (2001)
Derive estimates of trans fatty acid intake from a large, nationally representative sample using dietary recall or record information and up-to-date tables of food composition.
Not specified
Not specified
Recruitment
Data used from 1989-91 Continuing Survey of Food Intakes by Individuals
Study Design
- Three-year survey with a stratified sample from the 48 conterminous states and Washington DC
- Trans fatty acid content of foods calculated from a USDA database
- An average of three-day dietary recalls taken during all seasons and all days of the week.
Statistical Analysis
- Daily intake of fatty acids from all food sources
- Intake levels corresponding to the estimated 10th and 90th percentiles
- Intakes generated for nine age-sex groups
- Weights developed for the 1989-1991 CSFII used for all data analyses.
Timing of Measurements
Each subject surveyed once
Dependent Variables
Trans fatty acid intake, using data from TAS-DIET, US module (Technical Assessment systems International Research System, Iowa State University)
Independent variables
- Dietary intake assessed by trained interviewers using 24-hour recall and diet records for two days previous to interview
- Data used only from subjects who supplied data for three days of intake.
Control Variables
None
- Final N: 11, 258 subjects
- Attrition: Not applicable
- Age: Age three and up
- Demographic Data: Not reported here
- Anthropometric Data: Not reported here
- Location: Lower 48 states, USA.
Age and Sex Group | Mean intake of total trans fatty acids, g | Percent of total fat | Percent of total energy |
Boys and girls age 3 through 5 years | 4.1±0.12 | 7.5 | 2.6 |
Boys and girls age 6 through 11 years | 5.3±0.13 | 7.7 | 2.7 |
Boys age 12 though 19 years | 7.1±0.37 | 7.6 | 2.8 |
Girls age 12 through 19 years | 5.1±0.16 | 7.6 | 2.7 |
Men age 20-49 years | 6.6±0.16 | 7.1 | 2.6 |
Women age 20-49 years | 4.6±0.01 | 7.4 | 2.6 |
Men age 50-69 years | 5.8±0.19 | 7.3 | 2.6 |
Women age 50-69 years | 4.2±0.13 | 7.5 | 2.6 |
Mean and women age 70 years and older | 4.5±0.12 | 7.9 | 2.6 |
The 90th percentile for trans fatty acid intake was 9.4g per day for the total sample.
On average, the US population consumes a mean value of 5.3g trans fatty acids per day, or approximately 2.6% of their total energy and 7.4% of their total fat energy intakes. Approximately 20-25% of the trans fatty acids are from naturally occurring sources.
Government: | National Institutes of Health | ||
Not-for-profit |
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This paper did not identify food sources of trans fatty acids.
Quality Criteria Checklist: Primary Research
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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? | No | |
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) | 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? | 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.) | 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? | N/A | |
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? | N/A | |
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? | 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? | 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? | 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? | N/A | |
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 | |