Obesity, high blood sugar, and high blood pressure are leading to nearly 50% more years of healthy life lost to disease or premature death than in 2000, according to a major international study. The Global Burden of Diseases, Injuries and Risk Factors Study 2021, published in The Lancet, used data from 204 countries and territories to identify the leading causes of illness and early death worldwide, measured in disability-adjusted life years (DALYs).
While the number of years lost due to factors associated with undernutrition for mothers and children, such as stunting or wasting, dropped by 71.5% over the same period, the study highlights a significant shift in global health challenges as populations age and lifestyles change. Air pollution remained the biggest risk factor in both the 2000 and 2021 data.
The study revealed that ill-health among 15-to-49-year-olds is increasingly attributable to a high body-mass index (BMI) and high blood sugar—key risk factors in developing diabetes. “Future trends may be quite different than past trends because of factors such as climate change and increasing obesity and addiction,” said Liane Ong, lead research scientist at the Institute for Health Metrics and Evaluation at the University of Washington, which led the study.
Despite the global shift, the study found that the results were not uniform. For instance, undernutrition remains a significant risk factor in sub-Saharan Africa. The accompanying study from the Global Burden of Diseases team also predicted that life expectancy is expected to rise by 4.5 years by 2050, from 73.6 years to 78.1 years, with the most significant increases in countries with currently lower estimates, leading to a convergence in life expectancies around the world.
However, the study also forecasted that while people will live longer, they are likely to experience more years in poor health. This poses a growing challenge for global health systems to not only extend lifespan but also improve the quality of life during those additional years.