Worldwide obesity rates have almost doubled since 1980, but some countries show improvements in high blood pressure, cholesterol

Obesity rates around the world have about doubled between 1980 and 2008, but not all the news is bad--some countries have shown a decline in average blood pressure and cholesterol levels and a leveling off of body mass index.

The news comes via several studies released Thursday in the Lancet, which detail how various countries and regions are faring in terms of BMI, blood pressure and cholesterol levels. Overall, between 1980 and 2008, global BMI increased on average 0.4 to 0.5 kilograms (about 0.9 to 1.1 pounds) per decade for men and women. Pacific Islanders have on average the highest BMI scores in the world.

In 1980, 4.8% of men and 7.9% of women around the world were obese; in 2008 those numbers rose to 9.8% of men and 13.8% of women. That translates into more than one-tenth of the world’s adult population being obese in 2008, with the edge being given to women over men, 297 million versus 205 million, or about half a billion adults across the globe.

People in the United States have the highest BMI among high-income countries. New Zealand came in second, and Japan had the lowest BMI scores. In high-income countries such as the U.S., New Zealand, Australia and the UK, BMI rates rose the most in the years of the study. However, rates in some high-income countries--Belgium, Finland, France and Switzerland--saw almost no rise. Rates in Italy may have actually dropped for women from 1980 to 2008.

People in South Korea, Cambodia, Australia, Canada and the U.S. had some of the lowest systolic blood pressure numbers (below 120 mmHg for women and below 125 mmHg for men), while the highest were seen in the Baltic and east and west African countries (135 mmHg for women and 138mmHg for men). Some Western countries had those high levels in the 1980s before they began to decline, the study reports. Researchers said those increases and decreases may be due to salt intake versus fruit and vegetable intake, obesity levels and blood pressure medication.

The news about cholesterol was good for people in the U.S., Canada, Sweden and Greece--these were among the high-income Western countries with the lowest cholesterol levels. But Japan, another high-income country, has seen average cholesterol levels among men and women increase since 1980 to Western European levels circa 2008 (some Western European countries had the highest cholesterol levels). Singapore and China also saw cholesterol levels rise, but at varying rates. This, said the study authors, may be chalked up to eating more animal products, particularly fats.

“It’s heartening that many countries have successfully reduced blood pressure and cholesterol despite rising BMI,� said Majid Ezzati, professor of global environmental health at Imperial College London, in a news release. “Improved screening and treatment probably helped to lower these risk factors in high-income countries, as did using less salt and healthier, unsaturated fats. The findings are an opportunity to implement policies that lead to healthier diets, especially lower salt intake, at all levels of economic development, as well as looking at how we improve detection and control through the primary healthcare system.�