Sticking to a “rule of thumb” when pouring a glass of wine encourages people to pour less — regardless of gender or body mass index (BMI), according to new research published in the Journal of Drug Policy.
The findings took the Iowa State University and Cornell University researchers who led the study by surprise.
“We had every expectation that men would always pour more than women, no matter what,” says Doug Walker, an assistant professor of marketing at Iowa State. (That men generally consume more alcohol than women is consistent with previous research.)
What they found instead is that having a rule of thumb — only filling the glass half way, for example, or following the two-fingers-from-the-top rule — had such a powerful effect “that men using a rule of thumb at all levels of BMI actually poured less than women who were not using a rule of thumb,” says Walker.
The team asked 74 students and staff members to pour glasses of wine in different scenarios using multiple types of glasses (standard, wide, narrow, stem, no stem, all clear) and various pouring scenarios (holding the glass, glass set on the table, pouring with and without food). Participants were supplied with both red and white wine in bottles of varying degrees of fullness and asked to pour as much wine as they normally would.
Seventy percent of the participants used the half-glass rule and they poured 20 percent less than those who didn’t. “It’s a big difference,” says Smarandescu. Based on the findings, she believes using a rule of thumb could help prevent people from overconsumption of wine.
Will any rule of thumb work? The researchers only tested the half-glass and two-fingers rule, so they hesitate to make broader claims. But, says Smarandescu: “I can definitely say that if one used the fill-the-glass-to-the-top rule, they will drink a lot more.”