Such is the acceleration of obesity worldwide, the study’s authors believe there is no chance the world can meet the target set by the UN for halting the obesity rate. They called for an additional levy on high sugar and highly processed foods in order to slow the decline.
The study represents the most complete picture of trends in adult BMI, including, for the first time, severe and morbid obesity, which are of enormous clinical and public health interest.
Researchers from Imperial College London analysed a range of population-based studies that had measured height and weight in adults aged 18 years and older worldwide.
Individual’s BMI was calculated and compared among adult men and women from 1975 to 2014.
They found a significant increase, from 105 million obese people in 1975 to 641 million in 2014. The percentage of obese men had more than tripled since 1975 from 3.2% to 10.8%. In women, the figure had more than doubled, from 6.4% to 14.9%.
These figures represent 266 million obese men and 375 million obese women worldwide in 2014, with the worldwide population becoming heavier by approximately 1.5kg in every decade after 1975.
European obesity rates
Men and women in high-income English-speaking countries in 2014 were found to have substantially higher BMIs than those in continental Europe, whereas in 1975 their BMI had been similar or lower, especially for women.
By contrast with these large increases, the rise in women’s mean BMI was less than 0.2 kg/m² per decade in central Europe, southwestern Europe, and high-income Asia Pacific.
“The number of people across the globe whose weight poses a serious threat to their health is greater than ever before,“ said Professor Majid Ezzati, the senior author of the study from the School of Public Health at Imperial.
“This epidemic of severe obesity is too extensive to be tackled with medications such as blood pressure lowering drugs or diabetes treatments alone, or with a few extra bike lanes.”
“We need coordinated global initiatives – such as looking at the price of healthy food compared to unhealthy food, or taxing high sugar and highly processed foods - to tackle this crisis.”
While two previous studies have estimated global trends in the prevalence of overweight and obesity, the largest health benefits of weight management are achieved by shifting the population distribution of BMI.
One such report on mean BMI, which characterises distributional shifts, estimated trends to 2008, before the global target was agreed.
Over reliance on drugs
The study emphasised the seriousness of these findings, stating that rising BMI levels had little effect on mortality rates in high-income countries due to an overreliance on pharmacological treatment, which had helped reduce blood pressure, serum cholesterol and manage diabetes complications.
In low income countries, where health systems might not have the capacity to identify and treat hypertension, dyslipidaemia, and diabetes, obesity might have a larger effect on population health.
The study warned that high-income and middle-income regions were facing an epidemic of severe obesity, in which antihypertensive drugs, statins, and glucose lowering drugs would not be able to fully address the hazards of such high BMI levels.
“Present interventions and policies have not been able to stop the rise in BMI in most countries. The global non communicable disease (NCD) target on obesity, although ambitious in view of past trends, has engendered a new look at policies that could slow down and stop the worldwide increase in BMI,” the study said.
“To avoid an epidemic of severe obesity, the next step must be to implement these policies, and to systematically assess their effect.”
Source: The Lancet
Published online ahead of print, doi.org/10.1016/S0140-6736(16)30054-X
“Trends in adult body-mass index in 200 countries from 1975 to 2014: a pooled analysis of 1698 population-based measurement studies with 19·2 million participants.”
Authors: Majid Ezzati et al.