Bigger wine glasses linked to higher consumption, study suggests

British researchers have found that selling wine in larger glasses leads customers to drink more, even though the servings are the same as a regular-sized glass.

"It's not obvious why this should be the case,” lead researcher Rachel Pechey told EurekAlert. “One reason may be that larger glasses change our perceptions of the amount of wine, leading us to drink faster and order more.”

Researchers got a pub in Cambridge to serve the same amount of wine (175 ml) in small 250-ml glasses, in standard 300-ml glasses and in larger-than-average 370-ml glasses for two weeks at a time.

The volume of wine purchased daily was nearly 10 per cent higher during the two-week periods when it was sold in the largest glasses compared to the standard-size glasses.

The researchers didn’t find a significant difference in sales between the smaller glasses and standard-size glasses, although sales did go down somewhat with the smaller glasses.

The researchers also found that the correlation between higher sales and larger-than-average glasses was higher at the bar portion of the pub, where most glasses are poured by bartenders, than at the restaurant portion where most glasses are poured by customers from bottles.

The researches don’t know why the larger glasses were linked with higher sales, but posit that portions may be consumed faster because people perceive -- consciously or subconsciously -- that they got less than a “full” glass.

Public health implications

Alcohol consumption is a risk factor in major public health problems like Type 2 diabetes, cancer and liver disease, so “glass size might be an effective target for intervention,” according to the researchers.

“For example, ensuring that all glasses were below a certain size could be one criterion amongst alcohol licensing requirements,” they write, while stressing that more study is needed before policy changes can be recommended.

The study was conducted by researchers from Behaviour and Health Research Unit (BHRU) at the University of Cambridge and is published online in BMC Public Health.