The shape of the beer glass you drink from could affect how much alcohol you consume, according to new UK research.
Researchers from the University of Bristol found people take almost twice as long to polish off a beer in a straight-sided glass compared with a curved one. However it made no difference to drinking speed with lemonade.
Study author Angela Attwood asked 160 university students to drink from either a straight-sided or curved glass.
She believes people drink quicker from curved glasses because it's harder to judge the halfway mark of your drink and therefore how much you've drunk.
"People often talk of 'pacing themselves' when drinking alcohol as a means of controlling levels of drunkenness, and I think the important point to take from our research is that the ability to pace effectively may be compromised when drinking from certain types of glasses," Attwood said in a media release.
The study participants were shown various videos and had to complete a language test so they wouldn't know what they were being tested for.
Professor Dan Lubman, the director of Turning Point Alcohol and Drug Centre, told ninemsn that another big problem with gauging how much you've drunk is understanding standard drink sizes.
"There are solid recommendations from the government around safe drinking levels and how to reduce the risk of short and long term harms," he said.
"Because of different shapes of glass in terms of beer and wine, it's very difficult to properly assess the number of standard drinks you've had."
In Australia, a standard drink contains 10 grams of alcohol, which is found in 150ml of wine. A 285ml glass of beer (a pot or midi) has 1.1 standard drinks.
The Australian government recommends adults drink no more than four standard drinks on a single occasion.
"When we are confused by these glasses, it's really easy for people to drink lots more than they intended," Professor Lubman said.
"Plan before you go out and understand it can be difficult to keep track of if you're not vigilant about how much you are drinking."