Americans grew fatter at a faster pace than residents of any other wealthy nation since 1980, during a period when obesity worldwide nearly doubled, researchers found.
Almost 10 percent of the world’s population was obese in 2008, according to studies published today by the medical journal The Lancet. The percentage of people with uncontrolled hypertension, or high blood pressure, fell, with high-income countries showing a larger drop. Cholesterol levels declined in North America, Australia and Europe, but increased in East and Southeast Asia as well as the Pacific region, researchers said.
The rise in obesity, as measured by body mass index, is worrying and may lead to an increase in diabetes, said Majid Ezzati of Imperial College London, who led the research. Ezzati suggested taxing sugary drinks and sweets as well as rethinking transportation, such as adding bike lanes.
“We are at best buying some time” Ezzati said in an interview yesterday. “We have to get very serious about BMI, beyond good intentions.” Policy changes may begin to reduce obesity in as little as five years, he said.
The findings about Americans and obesity add to evidence that the U.S. has a weight problem. About 68 percent of American adults are overweight, raising their risk of diabetes, heart disease, high blood pressure and cancer, according to the 2008 National Health and Nutrition Examination Survey. Almost 34 percent are obese.
Researchers from Imperial College, Harvard University’s School of Public Health and other institutions analyzed government statistics and multinational studies to track changes in body mass index, cholesterol levels and blood pressure.
Body mass index considers a person’s weight relative to their height. A reading of over 30 is considered obese, while more than 25 is overweight.
In 2008, 9.8 percent of men and 13.8 percent of women globally were obese, compared with 4.8 and 7.9 percent respectively in 1980, the researchers found. Among rich nations in 2008, the U.S. had the highest BMI at 28 on average, followed by New Zealand. Japan had the lowest index, about 22 for women and 24 for men. Singapore residents were the second slimmest.
The U.S. saw the fastest rise of body mass, about 1 point per decade during the 28 years of the study, of any wealthy nation, the researchers found.
An increased body mass index is a risk factor for cardiovascular disease, diabetes, cancer and ailments of the muscles and the skeleton, leading to 3 million deaths worldwide annually, according to the studies. High blood pressure is the leading risk factor for cardiovascular deaths, killing 7 million each year, while high cholesterol leads to about 4.4 million deaths each year, the study said.
Controlling blood pressure, total cholesterol and smoking will cut cardiovascular disease rates, even if obesity and diabetes rise, Salim Yusuf and Sonia Anand of McMaster University in Canada, said in an accompanying editorial.
On average, Pacific Islanders have the highest body mass index in the world, reaching 34 to 35, 70 percent higher than countries in sub-Saharan Africa and countries in Southeast Asia. In Europe, Turkish and Czech women are the heftiest, while Swiss females were the slimmest.
The second study showed that blood pressure is highest in the Baltic region as well as East and West African countries. Portugal, Finland and Norway have the highest blood pressure readings of rich countries, while South Korea, Cambodia, Australia, Canada and the U.S. had some of the lowest.
Western European countries including Greenland, Iceland, Andorra, and Germany led global cholesterol levels. African countries have the lowest cholesterol.
Among high-income countries in the west, Greece has the lowest cholesterol for men and women, while the U.S., Canada, and Sweden also had low cholesterol.
The work is part of the Global Burden of Diseases, Injuries and Risk Factors Study, which is supported by the Bill and Melinda Gates Foundation. The study also received funding from the World Health Organization.