(CNN)The obesity epidemic has gone global, and it may be worse than most thought.
A new study in The Lancet says that if current trends continue, 18% of men and 21% of women will be obese by 2025.
In four decades, global obesity has more than tripled among men and doubled among women, the study says.
The paper compared body mass index trends from 1975 to 2014 in 200 countries.
• Odds are pretty high that your country has more obese people than underweight ones. More men were obese than underweight in 136 countries, and more women were obese than underweight in 165 of them.
• In 1975, 2.6% of the world's population was obese; in 2014, that number jumped to 8.9%.
• Obesity prevalence was less than 1% for men in two countries: Burundi and Timor-Leste. For women, Timor-Leste, Japan, Vietnam, North Korea, Cambodia, Laos and Bangladesh all had obesity prevalence under 5%.
• High-income English-speaking countries (Australia, Canada, Ireland, New Zealand, the United Kingdom and the United States) account for more than a quarter of the world's severely obese people. Coming in second, though, are the Middle East and North Africa, which is home to 26 million severely obese people, or 13.9% of the world's severely obese population.
• Forty percent to 50% of women in several Caribbean and Middle Eastern countries are obese.
• Make way for China. In 1975, China was 60th and 41st for severely obese men and women, respectively. In 2014, it was second for both.
• The United States still takes the cake. More than one in four severely obese men and one in five severely obese women lives in the country. By 2025, the study estimates, 43% of women and 45% of men in the United States will be obese.
• What chance does the United States have to stop the rise of obesity by 2025? Zero, the study says.
Find out here what the study projects for your country.
A previous version of this story incorrectly reported the range of time in which the study compared body mass index trends. The correct range is from 1975 to 2014.