National and state policies and the prevalence of adult obesity: A 30 year trend analysis in the United States

The concern with increasing obesity stems from the recognition that the population’s well-being is vital to a nation’s well-being by decreasing mortality, morbidity, reducing incidence of chronic diseases, and financial burdens on healthcare systems. Most of the existing literature on the effect of nutritional and taxation policies on obesity uses specific short timeframes or cross-sectional data. To fill the gaps in the literature, this study examines the association of national policies on nutritional guidelines, state taxes on soda, and state expenditures on recreational and park facilities with obesity over 31 years. Two research questions guide this study. First, to what extent did the USDA Food Guides from 1984 to 2014 influence adult obesity? Second, how did state policies on soda, and park and recreational facilities affect state-level adult obesity? Data from the Behavioral Risk Factor Surveillance System, United States Department of Agricultural (USDA) Food Guides, the Annual Survey of State and Local Government Finances, the Bridging the Gap, U.S. Census data, and the Current Population Survey are sources of the data used for the study. Logistic regression was used for the national-level analysis and generalized least squares with random effects regression was employed for the state-level analysis. The results show a clear significant association of the USDA food guides eras (Food Wheel 1984-1991; Pyramid 1992-2003; My Pyramid 2005-2010; My Plate 2010-2014) with national and state level rate of obesity. At both levels, the later the food guide era, the higher the likelihood of obesity or obesity rate. At the state level, there was no significant impact of state retail soda tax and state excise tax, and state expenditures for park and recreation on the state obesity rate. The results have significant implications for the development of food guides, policies on state soda taxes, and decisions on state parks and recreation facilities as venue of physical activities.