Kanazawa Satoshi
Department of Management, London School of Economics and Political Science, London, UK.
Curr Opin Endocrinol Diabetes Obes. 2014 Oct;21(5):339-44. doi: 10.1097/MED.0000000000000091.
The negative association between intelligence and obesity has been well established, but the direction of causality is unclear. The present review surveys the recent studies on the topic with both cross-sectional and longitudinal data in an attempt to establish causality.
Most studies in the area employ cross-sectional data and conclude (without empirical justification) that obesity causes intellectual impairment. The few studies that employ prospectively longitudinal data, however, uniformly conclude that lower intelligence leads to BMI gains and obesity. A close examination of three such studies, from three different nations (Sweden, New Zealand, and the UK), leaves little doubt that the causality runs from low intelligence to obesity.
The conclusion in previous studies that obesity impairs cognitive function stems from improper interpretation of a negative association between intelligence and obesity from cross-sectional studies. Results from the analyses of high-quality, population-based, prospectively longitudinal data firmly establish that low intelligence increases the chances of obesity.
智力与肥胖之间的负相关关系已得到充分证实，但因果关系的方向尚不清楚。本综述调查了近期该主题的横断面和纵向数据研究，试图确定因果关系。
该领域的大多数研究采用横断面数据，并得出（无实证依据）肥胖导致智力损害的结论。然而，少数采用前瞻性纵向数据的研究一致得出结论，即较低的智力会导致体重指数增加和肥胖。对来自三个不同国家（瑞典、新西兰和英国）的三项此类研究进行仔细研究后，几乎可以确定因果关系是从低智力到肥胖。
先前研究中关于肥胖损害认知功能的结论源于对横断面研究中智力与肥胖之间负相关关系的不当解读。基于高质量、以人群为基础的前瞻性纵向数据分析结果有力地证明，低智力会增加肥胖的几率。
