If you want to cut down on the amount of wine you drink, choose a narrow glass, experts say. And in this case, the experts are scientists, not bartenders.

Drinking from a wide glass might get you a heavier-handed pour, said researchers from Iowa State and Cornell universities.

Unlike a bottle of beer or a shot of spirits, a glass of wine is not an exact measure. So, the scientists set out to see what affects the size of a pour.

Participants in the study — 73 students and staff who regularly drank wine — were asked to pour what they considered a “normal” glass of wine. That’s 5 ounces, according to the National Institute on Alcohol Abuse and Alcoholism. When people were pouring into a wide wine glass, they poured about 12 percent more than if they poured into a narrow wine glass. The same was true when people held a glass, rather than pouring into a glass on the table. Researchers also found that people poured 9 percent more white wine into a glass than red, likely because of the contrast of color. Food and table settings had little or no effect on the amount, according to the study, which was published in the journal Substance Use and Misuse.

Bottom line: Measuring your consumption by the number of glasses could be a problem. “One person’s two is totally different than another person’s two,” said Douglas Walker, one of the study’s authors and an assistant professor of marketing at Iowa State.

It’s important to become aware of portions — just as people have for food, said Brian Wansink, another author and director of the Food and Brand Lab at Cornell. “If you want to pour and drink less wine, stick to the narrow wine glasses and only pour if your glass is on the table or counter and not in your hand,” he said. □