Enlarge By Tim Sloan, AFP/Getty Images An overweight man walks at the Montgomery County Agricultural Fair in Gaithersburg, Md. Americans are most obese among nations with advanced economies. The United States is the fattest nation among 33 countries with advanced economies, according to a report out today from an international think tank. Two-thirds of people in this country are overweight or obese; about a third of adults — more than 72 million — are obese, which is roughly 30 pounds over a healthy weight. Obesity rates have skyrocketed since the 1980s in almost all the countries where long-term data is available, says the report from the Organization for Economic Cooperation and Development (OECD), which works on policies to promote better economies and quality of life. Countries with the fastest obesity growth rates: the United States, Australia and England. "Obesity is a growing threat to public health in all the advanced countries throughout the world," OECD spokesman Matthias Rumpf says. Obesity causes illnesses, reduces life expectancy and increases health care costs, he says. Obesity increases the risk of heart disease, diabetes, several types of cancer and other diseases. Obesity cost the U.S. an estimated $147 billion in weight-related medical bills in 2008, according to a study by government scientists. "We have to find the most effective and cost-efficient way to deal with the problem," Rumpf says. "Countries can learn from each other, and the best and most effective policies can be used in all countries." Among OECD's recommendations: •Individual lifestyle counseling by family doctors and dietitians to increase the life expectancy and quality of life for people who are obese or at risk of becoming so. "It costs a lot of money," Rumpf says, "but you get a lot for this money." •Health-promotion campaigns, compulsory food labeling and a serious commitment from the food industry to stop advertising unhealthy foods to kids. "There are a lot of these things going on in the U.S. already, but the question is (whether) you can adjust and redirect the policies to make them more effective," he says. "No one can fix the problem, but we can reduce it." Neville Rigby, director of the European Obesity Forum, says the OECD report "is important because it provides clear evidence that the way most countries have been approaching obesity has been doomed to failure." "Obesity must be tackled by a multi-pronged approach that involves a combination of strong policy measures at the same time as individual management issues are addressed by physicians and their teams," he says. The report "makes the case for a much more robust set of government and societal actions," Rigby says. If society waits for business and individuals to do what is really needed, "the obesity epidemic will simply get much, much worse." Guidelines: You share in the USA TODAY community, so please keep your comments smart and civil. Don't attack other readers personally, and keep your language decent. Use the "Report Abuse" button to make a difference. You share in the USA TODAY community, so please keep your comments smart and civil. Don't attack other readers personally, and keep your language decent. Use the "Report Abuse" button to make a difference. Read more