EAL

PWM: Foods and Nutrients (2006)

Citation:

Study Design:

Class:

- Click here for explanation of classification scheme.

Quality Rating:

Research Purpose:

To determine differences in dietary intake between overweight and non-overweight schoolchildren and differences in consumption during the day and in the course of the week.

Inclusion Criteria:

Children age 11 years in good health were randomly selected.

Exclusion Criteria:

Not specified.

Description of Study Protocol:

Sample was randomly selected. Further details regarding where sample was identified were not given.
Students and parents were asked to read an explanation of the study and to sign an informed consent.

Data Collection Summary:

Dependent variables: Weight-for-height (measured following standardized protocol); Overweight greater than 90^th percentile compared with reference values for children (Instituto de Investigacion…1985).
Independent variables: Dietary intake: total energy, energy distributed in the course of the day, average daily intake of the following dietary components: protein, carbohydrate, fat, saturated fat, monounsaturated fat and polyunsaturated fat, vitamins and minerals (seven-day food weighing method)
Control variables: None specified
Statistical analysis: Chi-squared tests and Student T-tests.

Description of Actual Data Sample:

Original sample: Not specified
Final sample: 32 children (16 males, 16 females)
Location: Spain
Race/Ethnicity: Not specified
SES: Not specified
Age: 11 years old.

Summary of Results:

Total Energy

Energy intake reported in the overweight group was significantly lower than non-overweight (8,948.7±2,549.3kJ per day vs. 9,590.1±1,884.9kJ per day; P<0.01).

Macronutrient Intake

Carbohydrate intake (reported as percent of total energy intake and as total grams) was significantly greater in the non-overweight schoolchildren (42.6 vs. 40.6%; P<0.01; 250.9±58.8g per day vs. 222.1±77.4g per day)
Fat and protein intake (reported as percent of total energy intake and as total grams) was not significantly different in both groups of children
There was no significant difference in fatty acid intake among overweight and non-overweight schoolchildren
The mean fiber intake was 13.16±8.2g per day and was significantly greater in the non-overweight schoolchildren (14.8±9.1g per day vs. 11.8±7.1g per day; P<0.01).

***Note fiber was not noted to be a dietary measure studied in this analysis.

No significant differences between overweight and non-overweight children were found for micronutrient intake.

Author Conclusion:

The data suggest the belief that overweight children eat more than non-overweight children is not correct
These findings suggest that the positive energy balance causing overweight is due possibly to a low energy output. However, the sample size studied is small, and future studies should assess a wider sample than that analyzed in the present study.

Funding Source:

University/Hospital:

Universidad del Pais Vasco (Spain)

Reviewer Comments:

Limitations:

Few details were given about the study protocol including inclusion and exclusion criteria, how subjects were selected, how many subjects were initially recruited
Small sample size
Statistical analyses could have been stronger; no variables noted to be controlled for.

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?	No
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?		???
	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.)	No
	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?	???
	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.)	???
	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?		???
	4.1.	Were follow-up methods described and the same for all groups?	???
	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%.)	???
	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?		Yes
	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.)	Yes
	5.3.	In cohort study or cross-sectional study, were measurements of outcomes and risk factors blinded?	Yes
	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?	???
	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?	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?		No
	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?	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)?	???
	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?	No
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?	No
10.	Is bias due to study's funding or sponsorship unlikely?		Yes
	10.1.	Were sources of funding and investigators' affiliations described?	No
	10.2.	Was the study free from apparent conflict of interest?	Yes