We investigated whether body composition, physical activity, physical inactivity, and cardiorespiratory fitness explained the presence of risk factors for cardiovascular disease (CVD) and type 2 diabetes in youth. Eighty-three obese children (6–12 years old) were classified as either low health risk (LHR; n = 30) or high health risk (HHR; n = 53) based on the absence/presence of metabolic risk factors that included measures of dyslipidemia, insulin resistance, and elevated blood pressure. Along with demographic and anthropometric data, body composition, physical activity, physical inactivity, and cardiorespiratory fitness variables were assessed. Risk factor clustering was evident in this sample with 24/83 (29%) possessing at least 2 risk factors. Percent body fat did not differ between the LHR (38.5%) and HHR (39.8%) groups, but total fat mass, total fat-free mass, and central body fat mass were greater in the high health risk group. The strongest predictor for the presence of risk factors was central body fat accumulation. Physical activity, physical inactivity, and cardiorespiratory fitness were unable to predict metabolic risk. Overall, we found that risk factors for CVD and type 2 diabetes were common and that body fat mass and central body fat distribution, in particular, were more important than physical activity, physical inactivity, and cardiorespiratory fitness in predicting metabolic risk in obese children.
Geoff D.C. Ball, J. Dru Marshall and Linda J. McCargar
Anita Durksen, Shauna Downs, Rebecca Mollard, Laura Forbes, Geoff D.C. Ball and Jon McGavock
Physical activity interventions targeting weight status have yielded mixed results. This variability may be attributed to compensatory changes in dietary patterns after increasing physical activity (PA) levels. Therefore, we sought to determine whether dietary patterns varied with time spent in vigorous-intensity PA in youth.
Cross-sectional analysis of 330 youth enrolled in a school-based prospective cohort in central Alberta. Physical activity was assessed with waist mounted accelerometers (Actical) worn for 7 days. Main outcomes included consumption of unhealthy foods and the unhealthy food index obtained from a validated web-based 24-hour dietary recall instrument. Secondary outcomes included macronutrient intake, food group (Canada’s Food Guide to Healthy Eating) intake, and diet quality.
Compared with youth participating in < 7 min/ day of vigorous physical activity, those achieving ≥ 7 min/day displayed no change in healthy or unhealthy food consumption. However, linear regression suggests a modest association between diet quality and vigorous-intensity PA.
These data demonstrate that in this cohort of Canadian youth, time spent being physically active is associated with healthier dietary patterns and not with increased consumption of unhealthy foods.
Noé C. Crespo, Geoff D.C. Ball, Gabriel Q. Shaibi, Martha L. Cruz, Marc J. Weigensberg and Michael I. Goran
Acculturation has been implicated to be associated with physical activity (PA) behaviors in adults; little is known, however, with respect to the pediatric population. The purpose of this study was to determine whether cardiorespiratory fitness (VO2max) and/or PA were associated with acculturation status in overweight Hispanic children. In a sample of 144 children 8–13 years old, acculturation status was determined by place of birth: foreign born (n = 17), 1st generation (n = 101), or 2nd/3rd generation (n = 26), and by questionnaire: less assimilated (n = 76) or more assimilated (n = 34). VO2max was measured using a treadmill protocol, PA was assessed by questionnaire, and body composition by DEXA. ANOVA and ANCOVA were used to determine unadjusted and adjusted group differences, respectively. After adjusting for covariates, the 2nd/3rd generation group had significantly higher VO2max compared with the 1st generation group: 2.26 ± 0.20 L/min vs. 2.15 ± 0.19 L/min, p = .03. No differences were noted for PA, however. Acculturation to the U.S. is associated with higher VO2max in overweight Hispanic children. Longitudinal analyses are needed to determine whether these fitness differences confer protective health effects in this at-risk population.