A recent study of ours published in BMC Public Health, found that when the same portion of wine was served in a larger, rather than smaller, glass, wine sales increased by almost 10%. But how does a larger glass lead to increased sales or consumption? One possibility, suggested by another recent study, is that the same portion of wine in a larger, rather than smaller, glass is perceived as a smaller amount. This perceptual effect could lead to changes in drinking behavior – for example, larger glasses might encourage faster drinking, lessen satisfaction with the amount served, or increase the pleasure associated with drinking the wine. We wanted to examine these possible mechanisms.
Our recent Cochrane review found that larger portion sizes and tableware increased consumption of food and non-alcoholic drinks, but found no evidence relating to consumption of alcohol. If larger glasses increase alcohol sales as suggested by our recent study increasingly large glasses could counteract policies and regulations aimed at curbing alcohol consumption. Given that alcohol is associated with an increased risk of diseases such as type 2 diabetes, cancer and liver disease, reducing the amount consumed would lead to significant health benefits.
In this study, published today in BMC Psychology, we randomized female university students to drink a fixed portion of red wine (175 ml) in a larger (370 ml) or smaller (250 ml) wine glasses of the same design, in a lab-based setting. We observed their micro-drinking behavior (drinking speed, number and duration of sips) using video recordings and assessed their satisfaction and pleasure with the wine they were served using self-report measures.
We found no evidence that consuming wine from a larger, in comparison to a smaller glass, alters micro-drinking behavior, satisfaction or pleasure. Nonetheless, the results showed that regardless of glass size, faster drinking and greater pleasure increased the desire to drink further.
Further research is needed to determine whether a larger glass increases consumption by encouraging faster drinking and increasing pleasure in naturalistic settings such as bars or pubs, and with a more representative sample.
If clear mechanisms for how larger wine glasses may increase alcohol consumption are established, this would clarify the circumstances under which glass size may have an effect. This might inform local policies, for example, larger glass sizes served in licensed premises could be capped in order to limit alcohol consumption.