Pediatric Weight Management

Pediatrics and Physical Activity


Fontvieille AM, Kriska A, Ravussin E. Decreased physical activity in Pima Indian compared with Caucasian children. International Journal of Obesity 1993;17: 445-452.

PubMed ID: 8401746
Study Design:
Cross-Sectional Study
D - Click here for explanation of classification scheme.
Quality Rating:
Neutral NEUTRAL: See Quality Criteria Checklist below.
Research Purpose:

The purpose of this study was to compare physical activity between Pima Indian children, a population of children highly prone to obesity, and Caucasian children.

Inclusion Criteria:
Good health as assessed by a questionnaire.
Exclusion Criteria:

Not Specified

Description of Study Protocol:

Statistical Analyses:

Group effects were tested by parametric or non-parametric tests. Spearman rank order correlation coefficients were used to assess the association between estimates of physical activity or television viewing and measures of obesity.

Multiple regression analyses were used to assess the impact of physical activity on body fatness, independently of sex and race which were treated as group variables.

Data Collection Summary:

Dependent Variables

  • Body fat (BIA and skinfolds – done on left side of body for right handed children and right side of the body for left handed children) 
  • Circumferences were measured for waist, thigh, arm and calf.

Independent Variables

  • Ethnicity (Pima/Caucasian)
  • Physical Activity – Interview with the child.  How much time devoted to PA in the last week and in the last year – “hour per year of activity”
  • Interview with the parent – rating scale representing their typical level of activity (0 = inactive, 3 = moderate, 6 = heavy, 9 = vigorous)
  • TV – as part of the activity questionnaire, children rated how much time they spent in each of the following activities (TV was one of those activities)
Description of Actual Data Sample:

N: 42 Caucasian children (21 male/21 female) and 43 Pima Indian children (22 male/21 female)

Age: Pima Indian children: 9.9 +/- 1.1 years; Caucasian children 9.7 +/- 1.2 years

Location: Phoenix area, Arizona

Summary of Results:

Physical Activity

Pima Indian girls had significantly lower past year sport leisure activity (P <.01) and spent significantly more time watching television than Caucasian girls (P <.05). 

Pima Indian boys and girls showed significantly lower reported past week sport leisure activity (P < .05) and a lower number of performed physical activities than Caucasians (P <.01)

In Pima boys, past year sport leisure activity (collected from the child) correlated negatively with percentage of fat (r = -.56, p < .01) and physical activity negatively correlated with waist/thigh ratio (r = -.59, p <.05)

In Caucasians, the PA level (collected from parents) inversely correlated with percentage of body fat (r = -.43, p <. .01), the sum of skin folds (r = .40, P<.02) and the fat mass (r = -.37, p < .03).

Multiple regression analysis indicated a significant part of the variance in percentage of body fat was explained by race (Pimas had a significantly higher amount of body fat than Caucasians) (P < .0001) and by sport leisure activity (P < .05).   No interaction was found.  Therefore the independent impact of activity on body fatness was similar in both races.

TV Watching

Time spent watching TV was positively correlated with waist/thigh ratio in Caucasian boys (r = .48, P < .05) and girls (r = .48, P < .05).  In Caucasian girls, a positive correlation was found between television viewing and percentage body fat (r = .47, P < .02)

No relationship was found between TV viewing and obesity in PIMAS.

Author Conclusion:

Obesity was positively correlated with the time spent watching TV. In Caucasians, the children who had more centralized fat watched more TV.

In the Pima children, a negative relationship between percentage of body fat and time spent playing were observed. In Caucasians, physical activity level or the time spent playing were inversely correlated with the sum of the skinfolds.

Overall conclusion:

Pima children are less involved than Caucasian children in physical activity and spend more time watching TV.  Although cause and effect can not be determined, the existence of obesity is linked in this study to the decrease of PA and increase in TV viewing.
Funding Source:
Miles Laboratory, BSN-General Biscuit (France)
Food Company:
Pharmaceutical/Dietary Supplement Company:
University/Hospital: Pierre and Marie Curie University (France), Hotel-Dieu Hospital (France)
In-Kind support reported by Industry: Yes
Reviewer Comments:


  • The interviewed both parents and children but in some instances (TV viewing) got different answers which left them with the responsibility of determining who was more accurate.
  • They also asked children to recall activity over the past year. That is a very long time to recall.  It was also calculated based on the number of hours they had the previous week, but it is possible that that week was not representative of every week.  The authors commented that they had tried to control for seasonal variations but no detail was given as to how this may have been controlled for.


  • Had both parent and child measures of TV viewing.
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? N/A
  3. Is the focus of the intervention or procedure (independent variable) or topic of study a common issue of concern to dieteticspractice? N/A
  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? N/A
  1.2. Was (were) the outcome(s) [dependent variable(s)] clearly indicated? N/A
  1.3. Were the target population and setting specified? N/A
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? N/A
  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? N/A
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? 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? 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.) 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? Yes
  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%.) N/A
  4.3. Were all enrolled subjects/patients (in the original sample) accounted for? N/A
  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? N/A
  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? 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? 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? 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? N/A
  6.8. In diagnostic study, were details of test administration and replication sufficient? Yes
7. Were outcomes clearly defined and the measurements valid and reliable? No
  7.1. Were primary and secondary endpoints described and relevant to the question? N/A
  7.2. Were nutrition measures appropriate to question and outcomes of concern? No
  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? N/A
  7.5. Was the measurement of effect at an appropriate level of precision? N/A
  7.6. Were other factors accounted for (measured) that could affect outcomes? No
  7.7. Were the measurements conducted consistently across groups? N/A
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? N/A
  8.2. Were correct statistical tests used and assumptions of test not violated? N/A
  8.3. Were statistics reported with levels of significance and/or confidence intervals? N/A
  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)? N/A
  8.6. Was clinical significance as well as statistical significance reported? N/A
  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? N/A
  9.2. Are biases and study limitations identified and discussed? N/A
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? N/A