Researchers found that people who eat out drink less when they are given a 300ml wine glass compared with a 370ml one. 

But the same effect was not noticed in bars where people consumed the same amount regardless of glass size.

The authors suggested that the effect might be more noticeable in restaurants as people are more likely to buy wine by the bottle, whereas in bars more wine is purchased by the glass. 

Five bars and restaurants in England participated in the studies between 2015 and 2018 analysed by researchers at the University of Cambridge,. 

In restaurants, when glass size was increased to 370ml, wine sales increased by 7.3 percent. 

Wine glasses have increased in size almost sevenfold over the past 300 years with the most marked increase being a doubling in size since 1990. 

During this time, the amount of wine consumed in England quadrupled. 

First author Dr Mark Pilling said: “Pouring wine from a bottle or a carafe allows people to pour more than a standard serving size. 

“If these larger portions are still perceived to be ‘a glass’, then we would expect people to buy and consume more wine with larger glasses. 

“As glass sizes of 300ml and 350ml are commonly used in restaurants and bars, drinkers may not have noticed the difference and still assumed they were pouring a standard serving. 

“In contrast, very large glasses, such as the 450ml glasses, are more obviously larger, so drinkers may have taken conscious measures to reduce how much they drink.”