GENEVA (Reuters) - Tackling the global obesity epidemic will require governments to take similar action to that many used to curb smoking, a top researcher said on Wednesday.

Two audience members watch the 2007 "Farm Aid" concert in New York September 9, 2007. REUTERS/Lucas Jackson

This could include regulations that restrict how companies market “junk” food to children and requirements for schools to serve healthy meals, said Professor Boyd Swinburn, a public health researcher who works with the World Health Organisation.

“The brakes on the obesity epidemic need to be policy-led and governments need to take centre stage,” Swinburn, a researcher at Deakin University in Australia, told Reuters at the 2008 European Congress on Obesity.

“Governments have to lead the way they did with the tobacco epidemic. We need hard-hitting messages.”

Action is urgent because, aside from sub-Saharan Africa, nearly every country has suffered a dramatic rise in the number of obese people in the past 30 years. That increase has likely been a tripling in many industrialized nations, he said.

The World Health Organisation classifies around 400 million people around the world as obese, 20 million of them children under the age of five.

Obesity raises the risk of diseases such as type 2 diabetes and heart problems, and is a problem that is piling pressure on already overburdened national health systems.

Swinburn says the food industry has largely driven the epidemic with a stream of processed products that are cheaper and better-tasting but filled with unhealthy ingredients.

Lack of physical fitness and exercise, while important, have played only a small role in explaining why the number of obese people has soared in recent decades, he said.

“Commercial drivers around food have been the biggest influence over the past 30 years,” he said. “The product, the price, the promotion and the placement has changed dramatically.

Swinburn urged governments to introduce policies similar to those taken against smoking. These have included tightly controlled marketing to children and regulations warning of the dangers of smoking on cigarette packages.

Obesity is persistent despite people being increasingly aware of the risks of being overweight, demonstrating the problem requires direct government intervention, he said.

“Governments have a number of ways to influence the behaviors of a population,” Swinburn said.

Among anti-obesity measures taken, New York has banned artery-clogging trans-fats from city restaurants and is forcing fast-food chains to display calorie counts on their menu boards.

Britain plans to spend 75 million pounds ($145 million) on a campaign encouraging healthy lifestyles as part of a wider anti-obesity strategy including compulsory cooking lessons for children and the promotion of exercise.