More than 2 billion of the total 7.5 billion people worldwide are now considered to be overweight or obese and suffering from related health issues, according to a new study published in the New England Journal of Medicine on Monday.

The United States was found to have the highest percentage of obese children and young adults in the world, at 13 percent, while Egypt is home to the highest percentage of obese adults, nearly 35 percent.

Researchers used body mass index – the ratio between a person’s height and weight – to determine whether a person is overweight or obese, and found that obesity has doubled in 73 countries since 1980 and has seen a continuous increase in most other countries.

“In our systematic evaluation of the health effects of high BMI, we found that excess body weight accounted for about 4 million deaths and 120 million disability-adjusted life-years worldwide in 2015,” reviewers wrote. “Nearly 70% of the deaths that were related to high BMI were due to cardiovascular disease, and more than 60% of those deaths occurred among obese persons.”

The sharp increase in body fat is due to a higher intake in sugary foods, compounded by urbanization and reduced physical activity.