Obesity affects 1-in-10 worldwide
The world's waistline continues to expand despite achievements in reducing hypertension and cholesterol levels, data indicate.
The study, published as a three part series in Lancet, measured changes in three heart disease risk factors — BMI, BP and cholesterol — between 1980 and 2008.
“This is the first time that anyone has tried to estimate trends in these major risk factors in every country in the world,” study researcher Goodarz Danaei, MD, of the Harvard School of Public Health, said in a press release.
Collaborative efforts from international researchers at multiple institutions and WHO reveal that the number of obese men increased from 4.8 in 1980 to 9.8% in 2008. Similarly, the number of obese women increased from 7.9% to 13.8% during the same time period.
Pacific island nations are the heaviest in the world, with average BMIs around 34 to 35 kg/m2, data indicated. Among developed nations, the United States has the highest BMI at more than 28 kg/m2, whereas Japan has the lowest at 22 kg/m2.
Although the researchers observed a modest reduction in the proportion of the world's population with uncontrolled hypertension, the actual number of people with elevated BP increased from 600 million to nearly 1 billion. They attribute these increases to population growth and longer life expectancies.
The United States joined Australia, Cambodia, Canada and South Korea on the list of countries with the lowest systolic BP levels — below 120 mmHg for women and below 125 mmHg for men.
Baltic and African countries had the highest systolic BP levels — about 135 mmHg for women and 138 mmHg for men — levels once common among Western European countries in the 1980s.
Reductions in average blood cholesterol levels were observed in North America, Australia and Europe, but increased in East and Southeast Asia and the Pacific region, the researchers noted.
Greece had the lowest cholesterol levels among high-income countries (below 5 mmol/L). But other Western European countries, including Greenland, Iceland, Andorra and Germany, had the highest cholesterol levels in the world (around 5.5 mmol/L).
“It's heartening that many countries haves successfully reduced BP and cholesterol despite rising BMI,” said Majid Ezzati, PhD, of the Imperial College London. “Improved screening and treatment probably helped to lower these risk factors in high-income countries, as did using less salt and healthier unsaturated fats.”
Gretchen Stevens, DSc, of WHO, commented that while health officials know that diet and physical activity patterns have contributed to the rise in obesity, effective policies to reduce weight gain remain unclear. “We need to identify, implement and rigorously evaluate policy interventions aimed at reversing the trends or limiting their harmful effects,” she said.