Pediatrics and Physical Activity
Wardle J, Guthrie C, Sanderson S, Birch L, Plomin R. Food and activity preferences in children of lean and obese parents. Int J Obes 2001; 25: 971-7.PubMed ID: 11443494
To compare food & activity preferences in a large sample of young children from obese and lean families using parental obesity as a marker of the obesity-risk phenotype.
Because the children from the families with obese parents were not yet overweight, differences observed in the two types of families are more likely to be causes than effects of obesity.
Children aged 4-5 y, whose parents were either obese/overweight (mother’s reported BMI > 28.5 & father’s BMI > 25) or normal-weight/lean (both parents BMI < 25) were selected from a population sample of families with twin births. (Note: parental BMI was based on self-report at time child was aged 3-yr.)
Families were drawn from the TEDS which includes 10,000 pairs of twins born in England & Wales in 1994 & 1995.
Proposed Hypothesis: Early expression of obesity risk is through food and activity preferences, which provides a basis for later weight gain.
When the children were 4 or 5-y-old, families were visited in their home, where mothers and children were weighed & measured, mothers completed questionnaire instruments to assess their children’s eating and activity habits and preferences, children did a taste preference task, and children’s intake in a test snack was assessed.
High-risk children (children from families with obese/overweight parents) & Low-risk children (children from families with normal-weight/lean parents).
- Children’s % of fat & lean tissue (Bioelectrical impedance analysis)
- Children’s Food Preferences (Factor analysis of ratings of a list of 95 commons foods)
- Children’s Eating Style (Children’s Eating Behaviour Questionnaire)
- Children’s Food Intake (Frequency of intake of High-Fat, Low-Fat, High-Fiber & Low-Fiber Foods – Food Frequency Questionnaire)
- Meal size (Mother’s ratings)
- Intake of Palatable Foods Under Conditions of Satiety (Test Snack)
- Children’s Activity Preferences (mother’s rating)
Lean families were selected to come from the same areas of the country & to provide an approximate match in terms of social class (father’s occupation – manual verses non-manual occupation).
Initial N: 428 twin children; 200 from families with overweight/obese parents & 228 from families with normal-weight/lean parents.
Attrition (final N): dropouts not specified.
Age: 4-5 y
Ethnicity: not specified
SES: not specified
Anthropometrics: Age, gender and zygosity distribution were similar in high-risk & low-risk children
Location: England & Wales
Mother’s BMI calculated from measured height & weight was substantially higher than their BMI based on reported height and weight.
Weight (17.53 vs. 18.30; p=0.003) & BMI (15.93 vs. 16.56; p=0.000) were higher in the children of obese than lean families, but the difference in percentage body fat was not significant.
Children’s Food Intake
There were no group differences in frequency of intake of high-fat, low-fat, high-fibre or low-fibre foods.
High- and low-risk children were rated (by their mothers) as selecting similar-sized food portions.
The children of obese families were rated as enjoying low-impact (sedentary) activities more (t=2.06, p=0.04) and being less active than other children (t=2.37; p=0.02). They also spent more hours at the computer and watching TV. There were no differences in enjoyment of high impact activities.
|Government:||Biotechnology and Biological Sciences Research Council (UK)|
- Large sample size.
- No multivariate analysis done.
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?||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?||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)||N/A|
|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?||N/A|
|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?||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%.)||No|
|4.3.||Were all enrolled subjects/patients (in the original sample) accounted for?||No|
|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?||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?||N/A|
|5.4.||In case control study, was case definition explicit and case ascertainment not influenced by exposure status?||Yes|
|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?||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?||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)?||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?||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?||N/A|
|10.2.||Was the study free from apparent conflict of interest?||Yes|