WEDNESDAY, Aug. 27, 2014 (HealthDay News) -- Pouring half a glass of wine at a time may keep you from drinking too much, according to a new study.
Researchers asked 74 college students and staff to pour red and white wines in different settings and from bottles that had varying amounts of wine in them. The participants were told to pour an amount they considered normal.
Those who had a "rule of thumb" about how much to pour -- such as limiting it to half a glass or two fingers from the top -- poured less wine than those without set guidelines.
"About 70 percent of the people in the sample used the half-glass rule, and they poured significantly less, by about 20 percent," study author Laura Smarandescu, an assistant professor of marketing at Iowa State University, said in a university news release.
"It's a big difference. We would suggest using a rule of thumb with pouring because it makes a big difference in how much people pour and prevents them from overdrinking," she added.
The researchers also found that body-mass index (BMI) -- an estimate of body fat based on height and weight -- affected how much wine men poured. Among men without a rule of thumb, overweight or obese men poured 31 percent more, while those at the midpoint of the normal BMI ranges poured 26 percent more.
BMI did not affect how much women poured, but those at the midpoint of the normal BMI range poured 27 percent less when using the half glass rule than those who did not, according to the study published recently in the International Journal of Drug Policy.
Overall, men poured more wine than women, unless they had a half-glass rule.
"In this study, we had every expectation that men would always pour more than women, no matter what. But what we found is that the rule-of-thumb effect is so strong 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," Doug Walker, an assistant professor of marketing at Iowa State, said in the news release.
The U.S. National Institute on Alcohol Abuse and Alcoholism offers tips for reducing your drinking.