373 Adapted Physical Activity Quarterly, 2013, 30, 373-386 © 2013 Human Kinetics, Inc. Official Journal of IFAPA www.APAQ-Journal.com RESEARCH Body Mass Index Trends Among Adult U.S. Special Olympians, 2005–2010 John T. Foley State University of New York Meghann Lloyd University of Ontario Institute of Technology Viviene A. Temple University of Victoria This study examined temporal trends in body mass index (BMI) among United States adults with intellectual disability (ID) participating in Special Olympics from 2005 to 2010. In addition, the prevalence of obesity was compared with published National Health and Nutrition Examination Survey (NHANES) statistics. After data cleaning, 6,004 height and weight records (male = 57%) were available from the Special Olympics International Healthy Athletes Health Promotion database for the calculation of BMI. Rates of overweight and obesity were very high but generally stable over time. Compared with NHANES statistics, the prevalence of obesity was signifcantly higher for Special Olympics female participants in each data collection cycle. Integrated efforts to understand the social, environmental, behavioral, and biological determinants of obesity and among Special Olympics participants are needed. Keywords: obesity, overweight, adults, temporal trends, intellectual disability Body Mass Index (BMI) is an important health indicator and determinant of health for people with intellectual disabilities (ID; Sohler, Lubetkin, Levy, Sogho- monian, & Rimmerman, 2009; van Schrojenstein Lantman-de Valk, Linehan, Kerr, & Noonan-Walsh, 2007). The relationship between BMI and mortality has been described as U-shaped; with elevated mortality rates among individuals with low and high BMIs (NHBLI, 1998). At the higher end, a BMI of ≥ 30 is used to denote obesity because this cut-off point is associated with high to very high disease risk (e.g., type 2 diabetes, hypertension, cardiovascular disease, impaired mobility) John T. Foley is with the Department of Physical Education at the State University of New York in Cortland, NY, USA. Meghann Lloyd is with the University of Ontario Institute of Technology in Oshawa, Ontario, Canada. Viviene A. Temple is with the School of Exercise Science, Physical, and Health Education at University of Victoria in Victoria, British Columbia, Canada.