Pediatric Weight Management

Pediatrics and Physical Activity

Citation:

Garaulet M, Martinez A, Victoria F, Perez-Llamas F, Ortega RM, Zamora S. Differences in dietary intake and activity level between normal-weight and overweight or obese adolescents. JPGN 2000; 30: 253-258.

PubMed ID: 10749407
 
Study Design:
Cross-Sectional Study
Class:
D - Click here for explanation of classification scheme.
Quality Rating:
Neutral NEUTRAL: See Quality Criteria Checklist below.
Research Purpose:
To investigate the prevalence of overweight and obesity in an adolescent group representative of a rural Mediterranean area and to determine possible associations with energy and nutrient intakes & levels of physical exercise.
Inclusion Criteria:
  • Representative sample of adolescents in 14-18 y age group living in Torre Pacheco
Exclusion Criteria:

Students were excluded if they were not maintaining stable weight during the week of the study, for showing signs of any illness, or for taking any medication or supplements that might interfere with the results.

Description of Study Protocol:

A representative sample of adolescents was drawn from the secondary school of Torre Pacheco (Murcia), a rural Mediterranean area located in the southeast of Spain. To obtain the sample, 50% of the secondary schools with students representative of all socioeconomic levels of the area were selected. 50% were randomly selected & stratified by school grade & sex. The population selected was divided into two groups: normal-weight subjects with BMI < 23 and overweight or obese subjects with BMI > 23. Separation between groups was set as 23, according to the criteria of Rolland-Cachera et al. 1982 (overweight >=75th percentile for weight in Spanish adolescents and obese >=90th percentile).

Data Collection Summary:

Dependent:  BMI (measured ht & wt); Waist-to-hip ratio: Abdominal & thigh perimeters; Tricep skinfold; Upper arm circumference.

 

Independent: 

  • Diet intake (7-consecutive-days food record);
  • Physical activity (Baecke physical activity questionnaire);
  • Energy expenditure (WHO equation to est. BMR which is multiplied by an activity coefficient.
  • Underreporters were defined as persons with a reported ratio of energy intake to est. BMR < 1.05.

Control Variables: none reported

Statistical Analysis:  ANOVA (tested for differences by gender and normal vs overweight) & Pearson’s correlation.

Description of Actual Data Sample:

Original Sample:  331 students sampled from 900 students from all schools in the area: random selection stratified by grade and sex

Withdrawals/Drop-Outs:  none specified

Final Sample:  331 adolescents (192 girls & 139 boys)

Age: 14-18 years

Race/Ethnicity:  Spanish.

SES:  students representative of all socioeconomic levels of the area were selected.

Location:  rural Mediterranean area.

Summary of Results:

Total Energy:

Overweight boys & girls (based on BMI) had an apparently lower energy intake than their normal-weight counterparts, but they tended to underreport more often. (16% of OW boys & 17% of OW girls underreported intake compared to 1.3% of NW males & 11% of NW females).

Macronutrients:

  • Overweight boys reported lower carbohydrate intake (% kcal from CHO and g/day) than their normal-weight counterparts ; overweight girls reported lower absolute (g/day) carbohydrate intake but %kcal from carbohydrate was not significantly lower compared to normal weight girls
  • Overweight boys derived a greater percentage of their energy from fat and less from carbohydrate than their normal-weight counterpart.
  • Energy intake and fiber was lower in both normal and overweight girls compared to boys
  • No sig. association between % kcal from protein and overweight was observed, but overweight boys reported lower absolute (g/day) protein intake compared to normal weight boys
  • No sig. association was observed between WHR (body fat distribution) or TSF and energy, macronutrient, or fiber intake
  • Overweight & obesity were negatively related to physical activity level only among boys.

Physical Activity

  • OW boys engaged in sports significantly less than NW boys (p=0.033),
  • Overweight and obese girls showed levels of activity nearly identical with their normal-weight peers.
Author Conclusion:
There is a high prevalence of overweight & obesity in the adolescent population studied. The study shows an association between overweight & obesity and nutrient intake & activity level.
Funding Source:
University/Hospital: Consejeria de Sanidad, Instituto Luis Manzanares
Other: Caja de Ahorros de Murcia
Reviewer Comments:

Strengths: Representative sample.

Limitations: Analysis - The stated purpose of the analysis was to examine associations between energy intake and physical activity with obesity, so it is unclear why authors reported comparisons by sex rather than adjusting for sex in the analysis.

Conclusion that lower fiber intake in girls is associated with overweight and obesity is not supported by the data (p=0.46)

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) 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
 
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? Yes
  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) 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 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? 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.) 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? 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.) N/A
  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? Yes
  6.4. Was the amount of exposure and, if relevant, subject/patient compliance measured? No
  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? 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? 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)? N/A
  8.5. Were adequate adjustments made for effects of confounding factors that might have affected the outcomes (e.g., multivariate analyses)? Yes
  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? No
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