Lancet readers know that the world's population is getting heavier, but the detail in the latest overview of global trends in mean body-mass index (BMI) and the proportion of individuals classified as overweight and obese remains striking. In their pooled analysis of 1698 population-based studies, with more than 19 million participants representing most countries, the NCD Risk Factor Collaboration found that between 1975 and 2014 the mean age-corrected BMI increased from 21·7 kg/m2 to 24·2 kg/m2 in men and from 22·1 kg/m2 to 24·4 kg/m2 in women. The prevalence of obesity also increased from 3·2% in 1975 to 10·8% in 2014 in men and from 6·4% to 14·9% in women.
During the same period, global life expectancy at birth has increased from less than 59 years to more than 71 years—an increase of about a third of a year for each year that has passed. Although healthy life expectancy has increased somewhat less than overall life expectancy, it has still shown consistent global improvement. The common sense view that large increases in obesity should translate into adverse trends in health is not immediately obvious in the global data. The world is at once fatter and healthier.
Read Full Article »