Serving wine in larger glasses may encourage people to drink more, even when the amount of the drink remains the same, a new study suggests.
Researchers from University of Cambridge and University of Bristol in the UK found that increasing the size of wine glasses led to an almost 10 per cent increase in sales.
Alcohol consumption is one of the leading risk factors for disease and has been linked to conditions such as type 2 diabetes, cancer and liver disease.
Researchers carried out the study in The Pint Shop in Cambridge from mid-March to early July last year. The establishment has separate bar and restaurant areas, both selling food and drink.
Wine (in 125 millilitres or 175 millilitres servings) could be purchased by the glass, which was usually a standard 300 millilitres size.
Over the course of a 16-week period, the owners of the establishment changed the size of the wine glasses at fortnightly intervals, alternating between the standard (300 millilitres) size, and larger (370 millilitres) and smaller (250 millilitres) glasses.
Researchers found that the volume of wine purchased daily was 9.4 per cent higher when sold in larger glasses compared to standard-sized glasses.
This effect was mainly driven by sales in the bar area, which saw an increase in sales of 14.4 per cent, compared to an 8.2 per cent increase in sales in the restaurant, researchers said.
The findings were inconclusive as to whether sales were different with smaller compared to standard-sized glasses, they said.
“We found that increasing the size of wine glasses, even without increasing the amount of wine, leads people to drink more,” said Rachel Pechey from Cambridge.
“It is not obvious why this should be the case, but one reason may be that larger glasses change our perceptions of the amount of wine, leading us to drink faster and order more,” said Pechey.
“But it is interesting that we did not see the opposite effect when we switched to smaller wine glasses,” she said. The findings were published in the journal BMC Public Health.