Restricting glass size reduces alcohol consumption and could help prevent booze-related disease, researchers have found.
A study at the University of Cambridge has found that people cut their overall wine consumption by around 6.5% when drinking from smaller glasses.
Researchers at the university’s Behaviour and Health Research Unit recruited 260 households and monitored their consumption when using 370ml glasses versus 290ml over two 14-day periods.
They also analysed the difference in consumption levels among those taking wine from bottles of 75cl and 37.5cl in volume.
Participants were told that the study aimed to explore the impact of the different glass and bottle sizes on people’s perception of taste and enjoyment of wine.
This deception was intended to avoid influencing participants to deliberately drink less knowing their intake was being monitored.
Previous studies of drinking habits where people were restricted to drinking from 50cl bottles rather than the accepted standard 75cl size did find overall consumption fell.
The Cambridge study, funded by The Wellcome Trust, aimed to see if similar reductions would be found in drinking from 37.5cl bottles as well as when using smaller glasses.
Publishing their findings in the journal ‘Addiction’, the researchers state: “Alcohol consumption is a major contributor to premature death and disease globally.
“Reducing alcohol consumption at the population level would decrease the risk of a range of non-communicable diseases, including some cancers, cardiovascular disease and Type 2 diabetes.”
They note that the size of wine glasses has increased during the last three centuries and dramatically so during the last three decades.
Previous research analysing the impact of glass size on the amount of alcohol sold in restaurants found that sales were 17.4% higher when the same measure of wine was poured into bigger glasses.
An earlier study has indicated that providing food and fizzy drinks in smaller portions and packages decreased consumption.
The Cambridge researchers wanted to know if this affect could be replicated in wine consumption within the home where they say most wine in the UK is drunk.
They state: “Interventions that target aspects of the physical environments that cue unhealthy behaviour, such as product affordability, availability and size, have significant potential to have scalable impacts at a population level, including on reducing harmful alcohol consumption.
“In terms of alcoholic drinks, altering the size of containers in which wine is packaged, sold and served has the potential to reduce consumption.”
They found strong evidence that households drank less when issued with smaller glasses (down 6.5%) and that the quantity downed from half-size bottles was lower than from full-size bottles (3.6%) although they say the evidence for this was weaker.
In conclusion the scientists say: “If the effects of wine glass size on consumption are proved reliable with effects sustained over time, reducing the size of wine glasses used in homes could contribute to policies for reducing alcohol consumption.
“Regulating glass size—alongside serving size—in licensed premises is also a possibility, which could shift social norms for what constitutes an acceptable size of glass for use outside as well as at home.”