The proportion of adults aged 18-25yrs grew 1.5 per cent between 1999 and 2004 across Europe and the US, but numbers of this important group for alcoholic drinks producers are set to remain static for the next five years.
Even so, young adults' alcoholic drinking occasions are set to increase by 14 per cent up to 2009, with young women expected to continue leading the sector, according to new research from market analyst group Datamonitor.
The report highlighted rising disposable incomes and a desire for new experiences as the main reasons for drinking more.
Women aged 18-25 already drink 63 per cent more alcohol than the average female and consumption has increased from 110 litres in 1999 to 148 litres in 2004.
British women topped the pile, the report predicting they will be drinking 291 litres of alcohol per year by 2009 after already being well ahead of the average by consuming 216 litres of alcohol in 2004.
German women came second, drinking 200 litres of alcohol in 2004, while Italians were the most abstemious on 66 litres.
But, the Datamonitor report said drinks firms would have to work harder in the next five years to satisfy the growing diversity in young adults' drinking occasions.
"The concept of repertoire drinking states that consumers' drink choices are not defined by age or social status but by a combination of current need-states, venue, type of occasion and the company," it said.
The report said young men may have a repertoire of drinks that included a beer in the bar after work, wine over dinner with a partner, a shot of Sambuca in a club with friends and champagne to celebrate a work promotion.
Companies will, however, have to be careful when promoting new products with experimentation among young drinkers fairly low; suggesting firms may do better by devising variations of existing products.
On the upside for manufacturers' margins, rising disposable incomes hold significant opportunities for premium product development.
Sharing alcohol with others while 'entertaining-at-home' and going out are also predicted to crowd out the 'staying-in' category among young adult drinkers.