Behavior and Psychology
Obesity (2008) 16 8, 1809–1815. doi:10.1038/oby.2008.296
Overweight Is Associated With Decreased Cognitive Functioning Among School-age Children and Adolescents
Yanfeng Li1, Qi Dai2, James C. Jackson3,4,5 and Jian Zhang1,6
- 1Department of Epidemiology and Biostatistics, the Arnold School of Public Health, University of South Carolina, South Carolina, USA
- 2Department of Medicine, Vanderbilt Epidemiology Center, Institute for Medicine and Public Health, Vanderbilt-Ingram Cancer Center, Vanderbilt School of Medicine, Vanderbilt University, Nashville, Tennessee, USA
- 3Clinical Research Center for Excellence, VA Tennessee Valley Health Care System, Nashville, Tennessee, USA
- 4Division of Allergy, Pulmonary, and Critical Care Medicine, Vanderbilt University, Nashville, Tennessee, USA
- 5Department of Psychiatry, Vanderbilt University, Nashville, Tennessee, USA
- 6Division of Health and Family Studies, Institute for Families in Society, University of South Carolina, South Carolina, USA
Correspondence: Jian Zhang (JZHANG4@cdc.gov)
Received 27 February 2007; Accepted 22 September 2007; Published online 12 June 2008.
Abstract
Objective:
Childhood overweight and obesity have increased substantially in the past two decades, raising concerns about their psychosocial and cognitive consequences. We examined the associations between academic performance (AP), cognitive functioning (CF), and increased BMI in a nationally representative sample of children.
Methods and Procedures:
Participants were 2,519 children aged 8–16 years, who completed a brief neuropsychological battery and measures of height and weight as a part of the Third National Health and Nutrition Examination Survey, a cross-sectional survey conducted between 1988 and 1994. Z-scores were calculated for each neuropsychological test, and poor performance was defined as z-score <2.
Results:
The association between BMI and AP was not significant after adjusting for parental/familial characteristics. However, the associations between CF remained significant after adjusting for parental/familial characteristic, sports participation, physical activity, hours spent watching TV, psychosocial development, blood pressure, and serum lipid profile. Z-scores on block design (a measure of visuospatial organization and general mental ability) among overweight children and children at risk of overweight were below those of normal-weight children by 0.22 (s.e. = 0.16) and 0.10 (s.e. = 0.10) unit, respectively (P for trend <0.05). The odds of poor performance on block design were 1.97 (95% confidence interval: 1.01–3.83) and 2.80 (1.16–6.75), respectively, among children at risk or overweight compared to normal-weight peers.
Discussion:
Increased body weight is independently associated with decreased visuospatial organization and general mental ability among children. Future research is needed to determine the nature, persistence, and functional significance of this association.
