The Lancet
Aug 30, 2014 Volume 384 Number 9945 p715 – 828
http://www.thelancet.com/journals/lancet/issue/current

Comment
Africa’s child demographics and the world’s future
Jeffrey O’Malley, Tessa Wardlaw, Danzhen You, Lucia Hug, David Anthony
Preview
In 1950, only about a tenth of the world’s children lived in Africa.1 Within 50 years, that proportion almost doubled, and it is set to double again by the middle of the 21st century, leaving Africa with nearly a billion children younger than 18 years by 2050—37% of the worldwide total. By the end of the century, based on present trends, almost half of all children will live in Africa.

Global, regional, and national prevalence of overweight and obesity in children and adults during 1980—2013: a systematic analysis for the Global Burden of Disease Study 2013
Marie Ng PhD a, et al
Summary
Background
In 2010, overweight and obesity were estimated to cause 3•4 million deaths, 3•9% of years of life lost, and 3•8% of disability-adjusted life-years (DALYs) worldwide. The rise in obesity has led to widespread calls for regular monitoring of changes in overweight and obesity prevalence in all populations. Comparable, up-to-date information about levels and trends is essential to quantify population health effects and to prompt decision makers to prioritise action. We estimate the global, regional, and national prevalence of overweight and obesity in children and adults during 1980—2013.
Methods
We systematically identified surveys, reports, and published studies (n=1769) that included data for height and weight, both through physical measurements and self-reports. We used mixed effects linear regression to correct for bias in self-reports. We obtained data for prevalence of obesity and overweight by age, sex, country, and year (n=19 244) with a spatiotemporal Gaussian process regression model to estimate prevalence with 95% uncertainty intervals (UIs).
Findings
Worldwide, the proportion of adults with a body-mass index (BMI) of 25 kg/m2 or greater increased between 1980 and 2013 from 28•8% (95% UI 28•4—29•3) to 36•9% (36•3—37•4) in men, and from 29•8% (29•3—30•2) to 38•0% (37•5—38•5) in women. Prevalence has increased substantially in children and adolescents in developed countries; 23•8% (22•9—24•7) of boys and 22•6% (21•7—23•6) of girls were overweight or obese in 2013. The prevalence of overweight and obesity has also increased in children and adolescents in developing countries, from 8•1% (7•7—8•6) to 12•9% (12•3—13•5) in 2013 for boys and from 8•4% (8•1—8•8) to 13•4% (13•0—13•9) in girls. In adults, estimated prevalence of obesity exceeded 50% in men in Tonga and in women in Kuwait, Kiribati, Federated States of Micronesia, Libya, Qatar, Tonga, and Samoa. Since 2006, the increase in adult obesity in developed countries has slowed down.
Interpretation
Because of the established health risks and substantial increases in prevalence, obesity has become a major global health challenge. Not only is obesity increasing, but no national success stories have been reported in the past 33 years. Urgent global action and leadership is needed to help countries to more effectively intervene.
Funding
Bill & Melinda Gates Foundation.