INTRODUCTION: The risk of diabetes begins at a lower BMI among Asian adults. This study compares the prevalence of diabetes between the U.S. and China by BMI. METHODS: Data from the 2015-2017 China Nutrition and Health Surveillance (n=176,223) and the 2015-2018 U.S. National Health and Nutrition Examination Survey (n=4,464) were used. Diagnosed diabetes was self-reported. Undiagnosed diabetes was no report of diagnosed diabetes and fasting plasma glucose ≥126 mg/dL or HbA1c ≥6.5%. Predicted age-adjusted prevalence estimates by BMI were produced using sex- and country-specific logistic regression models. RESULTS: In China, the age-adjusted prevalence of total diabetes was 7.8% (95% CI=7.4%, 8.3%), lower than the 14.6% (95% CI=13.1%, 16.3%) in the U.S. The prevalence of diagnosed diabetes was also lower in China than in the U.S. There were no statistically significant differences in the prevalence of undiagnosed diabetes between China and the U.S. The distribution of BMI in China was lower than in the U.S., and the predicted prevalence of total diabetes was similar between China and the U.S. when comparing adults with the same BMI. The predicted prevalence of undiagnosed diabetes was higher in China than in the U.S. for both men and women, and this disparity increased with BMI. When comparing adults at the same BMI, there was little difference in the prevalence of total diabetes, but diagnosed diabetes was lower in China than in the U.S., and undiagnosed was higher. CONCLUSIONS: Although differences in BMI appear to explain nearly all of the differences in total diabetes prevalence in the 2 countries, not all factors that are associated with diabetes risk have been investigated.

In this issue of Pediatrics, Cunningham et al1 explore obesity incidence trends in school-aged children from kindergarten through fifth grade in 2 cohorts of the Early Childhood Longitudinal Study (ECLS). The earlier cohort was followed from 1998 to 2004 and the later cohort from 2010 to 2016. The ECLS results show an increase in incidence of obesity in the 2010 cohort compared with the 1998 cohort. Moreover, among children who entered kindergarten without obesity, 29% more non-Hispanic Black children developed obesity by fifth grade in the later cohort compared with the earlier one, whereas obesity incidence remained unchanged or decreased in other race and ethnicity groups.

BACKGROUND: The association between body mass index (BMI) and adiposity differs by race/ethnicity. OBJECTIVE: To examine differences in adiposity by race/Hispanic origin among US youth and explore how those differences relate to differences in BMI using the most recent national data, including non-Hispanic Asian youth. METHODS: Weight, height and DXA-derived fat mass index (FMI) and percentage body fat (%BF) from 6923 youth 8-19years in the National Health and Nutrition Examination Survey (NHANES) 2011-2018 were examined. Age-adjusted mean BMI, FMI and %BF were reported. Sex-specific linear regression models predicting %BF and FMI were adjusted for age, BMI category and BMI category*race/Hispanic origin interaction. RESULTS: %BF was highest among Hispanic males (28.2%) and females (35.7%). %BF was lower among non-Hispanic Black (23.9%) compared with non-Hispanic White (26.0%) and non-Hispanic Asian (26.6%) males. There was no difference between non-Hispanic Black females (32.7%) and non-Hispanic White (33.2%) or non-Hispanic Asian (32.7%) females. FMI was higher among Hispanic youth compared with non-Hispanic White youth. Among youth with underweight/healthy weight, predicted %BF and FMI were lower among non-Hispanic Black males (-2.8%; -0.5) and females (-2.0%; -0.3), compared with non-Hispanic White youth, and higher among Hispanic males (0.9%; 0.2) and females (2.0%; 0.5), while %BF but not FMI was higher among non-Hispanic Asian males (1.3%) and females (1.4%). Among females with obesity, non-Hispanic Asian females had lower %BF (-2.3%) and FMI (-1.7) than non-Hispanic White females. CONCLUSIONS: Differences in %BF and FMI by race/Hispanic origin were not consistent by BMI category among US youth in 2011-2018.

BACKGROUND: Data from the NHANES indicate that BMI has increased in some subgroups of children and adolescents in the United States over the past 20 y; however, BMI is an indirect measure of body fatness. OBJECTIVES: We assessed changes in DXA-derived measures of adiposity in a nationally representative population of US children and adolescents aged 8-19 y from 1999-2006 to 2011-2018. METHODS: Using data from the NHANES, we compared the means and distributions of DXA-derived percentage body fat (%BF) and fat mass index (FMI; fat mass/height2 in kg/m2) between 1999-2006 (n = 10,231) and 2011-2018 (n = 6923) among males and females by age group, race and Hispanic origin, and BMI categories. Estimates were standardized by age and race and Hispanic origin. RESULTS: From 1999-2006 to 2011-2018, mean %BF increased from 25.6% to 26.3% (change in %BF: 0.7%; 95% CI: 0.2%, 1.2%; P < 0.01) among all males, whereas mean %BF increased from 33.0% to 33.7% (change in %BF: 0.7%; 95% CI: 0.2%, 1.2%; P = 0.01) and mean FMI increased from 7.7 to 8.0 fat mass kg/m2 (change in FMI: 0.3 fat mass kg/m2; 95% CI: 0.0, 0.6 fat mass kg/m2; P = 0.02) among all females. Changes were not consistent across all age, race and Hispanic origin, and BMI categories. Both %BF and FMI increased among Mexican-American children and adolescents, but not other race and Hispanic origin groups. CONCLUSIONS: Among US children and adolescents, DXA-derived measures of adiposity increased from 1999-2006 to 2011-2018, albeit not consistently in every age, race and Hispanic origin, and BMI subgroup. These data reinforce the need to consider other measures, besides BMI categories, when studying adiposity in children and adolescents.

This study uses NHANES data to assess trends in obesity and severe obesity stratified by race and Hispanic origin among US residents from 1999 to 2018.