Sales of energy drinks have doubled in the last five years, according to recent research.

A report by food and drink consultancy Zenith International, released this week, shows that global energy drink volumes increased by 2% in 2008 to 3.9bn litres, almost double the 2.0bn litres sold in 2003.

Average growth over the past five years has been 14% a year.

North America is the leading region, with 37% of global volume in 2008, followed by Asia Pacific with 30% and West Europe with 15%. East Europe has made significant volume gains over the last few years and now accounts for a growing 6% share. Asia Pacific was the only region to experience a decline in 2008, with consumption falling by 18%. Sales dropped by 41% in Thailand, mainly because of the economic crisis, as many of energy drinks' biggest consumer group - truck drivers - were made redundant.

"Energy drinks remain a dynamic segment in the soft drinks market, with double figure rises in most regions," said Zenith's market intelligence director, Gary Roethenbaugh. "This is testament to the energy drink concept's staying power."

Mirroring the market's overall growth in recent years, consumption per person has also advanced rapidly, up from 0.4 litres in 2003 to 0.8 litres in 2008.

By 2013, Zenith estimates that the global market will reach 5.8bn litres, equivalent to 1.1 litres per person.

The 2009 Global Energy Drinks report also found that North America and Australasia have the highest regional consumption at 4.2 litres per person, while the US is the largest consumer of energy drinks, followed by Thailand. Indonesia is the third largest market, then China and the UK in fifth place.