The volume of wine that bar and pub customers drink in one session is reduced if the largest serving by the glass is removed, a study suggests.
Researchers say the discovery could nudge people to drink less alcohol, after finding people tend to consume the same number of glasses, regardless of the glass size.
They suggest that even a small cut in consumption could boost the health of the population. The number of women dying from alcohol-related diseases has soared in recent years, The Independent revealed this week.
Even when taking into account the day of the week and total revenue, the scientists found that removing the largest wine glass serving – usually 250ml – led to a drop in wine on average sold each day of around 420ml at any given pub or wine bar – a 7.6 per cent decrease.
They also found no evidence that people were making up for drinking less wine by buying more beer or cider.
The findings suggest that licensed premises did not lose money as a result of removing the largest serving size by the glass. This was perhaps down to the higher profit margins of smaller serving sizes of wine, the experts suggest.
Alcohol consumption is the fifth-largest contributor to premature death and disease worldwide. According to the World Health Organisation, the harmful use of alcohol led to around three million deaths worldwide in 2016.
First author Dr Eleni Mantzari, of the University of Cambridge, said: “It looks like when the largest serving size of wine by the glass was unavailable, people shifted towards the smaller options, but didn’t then drink the equivalent amount of wine.
“People tend to consume a specific number of units – in this case glasses – regardless of portion size.
“So someone might decide at the outset they’ll limit themselves to a couple of glasses of wine, and with less alcohol in each glass they drink less overall.”
Professor Dame Theresa Marteau, the study’s senior author, said: “It’s worth remembering that no level of alcohol consumption is considered safe for health, with even light consumption contributing to the development of many cancers.”
For the research, published in Plos Medicine, the team studied 21 licensed premises – mainly pubs – in London, Cambridgeshire, Southampton, Gloucester and Brighton and Hove for four weeks.
Managers at four of the premises received complaints from customers about the removal of the largest glass option, and the researchers say the alcohol industry would be likely to resist a nationwide policy.