LONDON (Reuters) – Obesity, high blood sugar and high blood pressure among other metabolic issues now lead to almost 50 percent more years of healthy life lost to either disease or premature death than in 2000, a major international study showed on Thursday.

Over the same period, the number of years lost due to factors associated with undernutrition for mothers and children, such as stunting or wasting, dropped by 71.5 percent.

The Global Burden of Diseases, Injuries and Risk Factors Study 2021, published on Thursday in The Lancet, used data from 204 countries and territories to identify the leading causes worldwide of illness and early death. These are measured in disability-adjusted life years, or “DALYs.”

The data shows a clear shift in global health challenges as populations age and lifestyles change, the authors said, although air pollution was the biggest risk factor in both the 2000 and 2021 data.

They also pointed out that the results were not uniform. Undernutrition remained a major risk factor in sub-Saharan Africa, for example.

Ill health among 15- to 49-year-olds worldwide was increasingly attributable to a high body-mass index (BMI) and high blood sugar—two risk factors in the development of diabetes, the authors said.

“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.

An accompanying study from the Global Burden of Diseases team predicted that life expectancy is expected to rise by 4.5 years by 2050, from 73.6 years to 78.1 years.

The biggest increases are likely in countries where the existing estimates are lower, meaning life expectancies are starting to converge around the world.

However, while people will live longer, they are likely to experience more years spent in poor health, the study forecast.

To learn more, read Obesity: An Unusual Epidemic.