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Citation:

McKenzie J, Dixon L, Smiciklas-Wright H, Mitchell S, Shannon B, Tershakovec A. Change in nutrient intakes, number of servings, and contributions of total fat from food groups in four- to 10- year-old children enrolled in a nutrition education study. J Am Diet Assoc. 1996; 96: 865-873.


PubMed ID: 8784330
Study Design:
Randomized Controlled Trial
Class:
A - Click here for explanation of classification scheme.
POSITIVE: See Research Design and Implementation Criteria Checklist below.
Research Purpose:
  • To determine change in nutrient intakes and the nutritional adequacy of these intakes compared with the recommended dietary allowance (RDA), gram of total fat contributed from food groups to the total fat intake and number of servings from food groups
  • To compare number of food group servings (before and after intervention) to current serving guidelines for children of the National Cholesterol Education Program (NCEP) in two intervention and two control groups.
Inclusion Criteria:

Children aged four to 10 with hypercholesterolemia and with normal cholesterol levels.

Exclusion Criteria:

None noted.

Description of Study Protocol:

Recruitment

Children were healthy, free-living subjects recruited via their pediatrician's offices in the suburbs of north Philadelphia.

Design

Prospective cohort. Upon enrollment, children were assigned randomly to one of four study groups.  

Dietary Intake/Dietary Assessment Methodology

Three 24-hour recalls were collected from the children via telephone interviews conducted by staff from the Penn State Nutrition Center at baseline and three months later. At both periods, the three dietary recalls included two week days and one weekend day selected randomly over a two-week period. Interviewers used the computer-assisted Nutrition Data System with food database version 4A and nutrient database version 19.

Intervention

Two groups of children with hypercholesterolemia received different forms of nutrition education.

  • One group (N=86) was the counseling group. The children in this group and their caretakers participated in one face-to-face counseling session with a Registered Dietitian (RD), received take-home materials (print) with dietary information and had free telephone access to the RD during the study.
  • The other group (N=88) was provided with an at-home parent-child auto-tutorial program (PCAT) that included 10 talking-book lessons with accompanying audiotapes about low-fat, healthful eating patterns, a booklet of paper and pencil activities for the child, and a manual for the parents
  • Both nutrition education programs advocated NCEP recommendations
  • A third group of children with hypercholesterolemia formed the at-risk control group (N=87) and received no formal nutrition education
  • A fourth group of age-gender-matched children with normal cholesterol levels formed the not-at-risk control group.

Statistical Analysis

  • Frequencies of all study group children combined (N=303) who achieved less than 67%, between 67% and 100% and greater than 100% of the RDA were compared via chi-squared analysis
  • Descriptive statistics were gathered for number of servings from 10 main food groups and five subgroups for baseline and three-month dietary data
  • Analysis of variance was performed to determine significant differences between nutrient and food group variables at baseline and three months among the four study groups
  • All analyses were done using SAS 6.0.

 

Data Collection Summary:

Timing of Measurements

 Baseline and three months after the start of the intervention.

Dependent Variables

  • Changes in mean nutrient and food group intakes compared with RDA. Mean intakes of nutrients were obtained from Nutrition Data Systems nutrient summary files generated from the three 24-hour recalls collected at baseline and three months.   
  • gram of total fat contributed from food groups to total fat intake
  • Number of food group servings before and after intervention compared to serving guidelines of NCEP. Foods were assigned to one of 10 food groups, including meats, eggs, dairy, fats and oils, breads, vegetables, fruits, desserts, beverages and sauces and gravies. Gram amounts of reported foods were converted to NCEP serving size and number of servings of all foods within the food groups was calculated.

Independent Variables

  • Face-to-face counseling session with take-home materials and free telephone access
  • At home parent-child auto-tutorial program with 10 talking book lessons.

Control Variables

  • At-risk control group consisted of kids with hypercholesterolemia with no counseling intervention
  • Not-at-risk control group consisted of age- and gender-matched children with normal cholesterol.
Description of Actual Data Sample:
  • Initial N: Not specified; reports "slight attrition occurred from baseline to three months"
  • Attrition (final N): 303
  • Age: 4- to 10-year-old children
  • Anthropometrics: Children in the test groups had hypercholesterolemia with elevated plasma LDL levels between the 80th and 98th percentiles for age and gender
  • Location: Suburbs north of Philadelphia.
Summary of Results:

 

Variables  

Dependent variable one: Changes in food group intake

Significant decline in number of fruit servings from baseline to three months in PACT group (P<0.0060. Other changes were not significant.

Dependent variable two: gram of total fat from food groups to total fat intake

PCAT group experiences a significant decline in plasma LDL at three months (P<0.05) than at risk control and counseling groups.

Dependent variable three: Change in mean nutrient intakes compared to RDA 

Significant change in mean percent RDA from protein, calcium, phosphorus and magnesium in PCAT, counseling and not-at-risk control group (P<0.025).

  

Author Conclusion:

Participants who lowered dietary fat intake after the intervention reported both qualitative and quantitative changes in food choices from several food groups. These choices did not significantly reduce their nutrient intakes.

Reviewer Comments:

The study findings support that children can reduce dietary fat intake without compromising nutrient adequacy. However, the study population consisted of upper-class white children from highly educated two-parent families. This may reduce the generalizability of study findings to different populations.


Research Design and Implementation 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 nutrition or dietetics practice?
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?
No
  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?
No
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 used? (Concurrent preferred over historical controls.)
???
  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 or cross-sectional 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. Criterion may not be applicable in some cross-sectional studies.)
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?
No
  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%.)
No
  4.3. Were all enrolled subjects/patients (in the original sample) accounted for?
???
  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?
???
  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.)
???
  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?
???
  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)?
???
  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