Heterogeneous contributions of change in population distribution of body mass index to change in obesity and underweight

From 1985 to 2016, the prevalence of underweight decreased, and that of obesity and severe obesity increased, in most regions, with significant variation in the magnitude of these changes across regions. We investigated how much change in mean body mass index (BMI) explains changes in the prevalence of underweight, obesity, and severe obesity in different regions using data from 2896 population-based studies with 187 million participants. Changes in the prevalence of underweight and total obesity, and to a lesser extent severe obesity, are largely driven by shifts in the distribution of BMI, with smaller contributions from changes in the shape of the distribution. In East and Southeast Asia…

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Who Becomes U.S. Mathematics Teachers: A Longitudinal Analysis of First-time Praxis® II Mathematics Content Knowledge Examinees

International audience; The U.S. uses the Praxis® tests to measure academic skills and the subject-specific content knowledge needed to be a teacher. This study examined Praxis® Mathematics Content Knowledge scores from 2006 to 2016 to describe patterns in who are becoming certified to teach mathematics in the country. Longitudinal analyses were used to discern patterns in the demographics of examinees and trends in exam performance across several demographic characteristics. The results reveal substantial differences in performance and pass rates between examinees of different genders, races, undergraduate majors, undergraduate GPAs, and census regions. From our analyses, we suggest severa…