PWM: Eating Behaviors of Children (2006)
To investigate if and how the relationship between feeding frequency and BMI in free-living teenagers aged 16-17 years old is dependent on the validity of recorded dietary intakes, BMI, self-reported dieting and body image.
- Described elsewhere (Crawley HF. Br J Nutr, 1993;70:15-26); subjects from the 1970 longitudinal birth cohort study.
- Students completed diet diary and had anthropometric measurements taken.
- Not described.
[Note: Titled as a "Short Communication"]
[Note: No blinding?]
- Feeding frequency (each eating occasion where calories consumed separated by at least 30 minutes, as assessed by a four-day diet diary).
- BMI (measured weight and height).
- Self-assessed body weight (feel under, normal or overweight).
- Gender (separate analysis)
- Under-reporting (non-dieting subjects who reported energy intake below 1.35 estimated BMR; removed from analysis)
- True dieting (same as above + reported dieting behavior; removed from analysis).
- N: 731 (298 males, 433 females)
- Age: 16-17 years
- Ethnicity: Not specified
- Other demographics: Not specified
- Location: England.
Feeding Frequency with Total Sample
- Inversely related to BMI for both males (P<0.005) and females (P<0.05)
- Feeding frequency was 6.5, 6.2 and 5.6 among males with BMI <20, 20-25 and >26, respectively
- Analogous numbers for females were 6.5, 6.3 and 6.4.
Feeding Frequency with Under-reporters (N=?) Removed
- Inverse relationship remained for both males (P<0.025) and females (P<0.05)
Feeding Frequency with True Dieters (N=26 males, 121 females) Removed
- Inverse relationship disappeared for males, but remained for females
- Overweight male dieters (N=11) had lower feeding frequency than other males
- Inverse relationship for females disappeared when normal or underweight females, who were not dieting but who considered themselves to be overweight (N=7), were removed from analysis.
The relationship observed in free-living populations, that feeding frequency is directly related to BMI, appears to be an artifact of reported eating behavior in overweight dieting males and among a group of normal weight, non-dieting females who feel overweight. Under-reporting of dietary intake alone, therefore, does not explain the apparent feeding frequency/BMI relationship among teenagers.
|University/Hospital:||University North London, The Royal Free Hospital School of Medicine (London)|
- Described how determined an eating occasion.
- No multivariate analysis
- Study recruitment and protocols and subject demographics not well described (described in other publication?)
- Convenience sample
- BMI measure not blinded
- Pulled the referenced Crawley paper to get more study details for quality grading, but did not answer most of questions (e.g., inclusion/exclusion criteria, sample selection).
Quality Criteria Checklist: Primary Research
|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)||N/A|
|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)||N/A|
|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?||No|
|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?||N/A|
|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?||No|
|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?||No|
|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?||No|
|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%.)||???|
|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?||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.)||No|
|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?||N/A|
|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?||N/A|
|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?||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?||Yes|
|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?||???|
|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)?||No|
|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?||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?||Yes|
|10.||Is bias due to study's funding or sponsorship unlikely?||Yes|
|10.1.||Were sources of funding and investigators' affiliations described?||???|
|10.2.||Was the study free from apparent conflict of interest?||Yes|