Leaner and less fit children have a better cardiometabolic profile than their heavier and more fit peers: The Healthy Growth Study

Background and aims: To examine differences in cardiometabolic risk factors between children of different BMI and fitness levels. Methods and results: From a representative sample of 1222 boys and 1188 girls, aged 9-13 years, anthropometric, body composition, physical activity, cardiorespiratory fitness, biochemical and blood pressure data was collected. The prevalence of overweight and obesity was 29.9% and 11.8% respectively. In both genders, plasma HDL cholesterol concentration was higher in the `leaner and less fit' group (lowest quartile of BMI and lowest quartile of fitness) compared to the `heavier and more fit' (highest quartile of BMI and highest quartile of fitness) and intermediate (all other children) groups (p < 0.05). Furthermore, the `leaner and less fit' groups in both genders had lower triacylglycerol concentration, total-to-HDL cholesterol ratio, HOMA-IR, insulin and systolic blood pressure levels compared to the ` heavier and more fit' and/or intermediate groups. Similar trends were observed for hypertension in boys and insulin resistance for both genders. Finally, the effect size of being ` leaner and less fit' on serum levels of cardiometabolic risk indices was mainly small to medium (i.e. Cohen's d 0.2-0.5). Conclusion: Leaner and less fit boys and girls had better cardiometabolic risk profiles than their heavier and more fit peers, probably suggesting a higher importance of leanness over fitness in children from a cardiometabolic health benefit perspective. (C) 2013 Elsevier B. V. All rights reserved.