OBJECTIVE: To systematically examine time trends and disparities in prevalence and projected adiposity and obesity (OB) measures in the US by socio-economic and ethnic groups, and geographic region.
METHODS: We analyzed 1999-2016 National Health and Nutrition Examination Survey (NHANES) and 2011-2016 Behavioral Risk Factor Surveillance System (BRFSS) data, and conducted projections for US adults and children. Standard definitions were used to classify overweight (OW), OB, and severe obesity (SOB) including based on BMI cut-points and percentiles. Central obesity (CO) was assessed using waist circumference cut-point in adults and waist-height ratio cutoff in children.
RESULTS: While OB prevalence has consistently risen since 1999, considerable disparities were detected across groups and regions. Among adults, men’s OB (33.7%) and OW/OB (71.6%) leveled off in 2009-2012, but resumed their increase to 38.0%/74.7%, respectively, in 2015-2016. Women showed un-interrupted increases in OB and OW/OB prevalence since 1999, reaching 41.5% and 68.9%, respectively, in 2015-2016. SOB levelled off in 2013-2016 (men: 5.5-5.6%; women: 9.7-9.5%), after annual increase of 0.2% since 1999. Non-Hispanic (NH) blacks had highest levels of OB/SOB among women and SOB among men. Boys’ OB prevalence rose continuously to 20.6% and SOB to 7.5% in 2015-2016, unlike girls. If trends continue, by 2030, most of Mexican American will be OW/OB; ~50% of adults will be OB, while ~33% of children (aged 6-11) and ~50% of adolescents (aged 12-19) will be OW/OB. During 1999-2014, CO was steadily rising overall and is projected to reach 55.6% in men and 80.0% in women, 44.0% among girls and 39.0% among boys by 2030. BRFSS data show regional differences in adult obesity prevalence (2011-2016) and across ethnicities, with the South (32.0%) and the Midwest (31.4%) showing the highest rates.
CONCLUSIONS: US obesity and overweight prevalence has been on the rise in recent years, with a brief leveling-off in 2009-2012. Wide disparities exist across sex, age, race/ethnicity and geographic region. Sustainable, effective, and culturally-tailored interventions are needed.