A study in the April 2005 issue of Alcoholism: Clinical & Experimental Research confirms that college students tend to overestimate volumes, over-pour drinks, and under-report levels of consumption. However, educational feedback regarding definitions of standard drinks appears to improve students' understanding of how much they actually drink.
"Just about everything we know about how much college students drink comes from survey studies," said Aaron White, assistant professor in the department of psychiatry at Duke University Medical Center and first author of the study. "We ask them to tell us how much they drink and we assume that their answers are totally accurate. In order for students to be accurate, they have to know how much alcohol constitutes a single serving. It turns out that they don't. When we ask them to pour us drinks of different types, they tend to pour too much.
"When we ask them to simply define how many ounces there should be in a single drink, they tend to give us numbers that are way too big. This tells us a few things. The first is that we have totally failed to teach students some of the most basic information about alcohol - what a single serving is. It also tells us that students' answers on alcohol surveys are probably inaccurate. How could they be if researchers and students have different definitions of how big a single serving is?" A "standard drink" is generally defined as a beverage that contains 0.6 ounces of pure alcohol. The most commonly used standard drinks are 12 ounces of five-percent beer, five ounces of 12-percent wine, or 1.5 ounces of 40-percent (80 proof) distilled spirits.
"The problem is that a typical drinker probably doesn't think this way," said White. "To many people, a 'drink' is one serving regardless of how big it is. Someone who has had four gin and tonics would probably give the same answer on an alcohol survey as someone who has had four Long Island iced teas, when in fact the latter could contain three times as much alcohol as the former."
For this study, researchers recruited 133 (78 males, 55 females) undergraduate students to complete an alcohol survey as well as "free pour" a single beer, glass of wine, shot of liquor, or the amount of liquor in a mixed drink. Roughly half of the subjects received feedback regarding their definitions of standard drinks. All participants were then resurveyed about their recent alcohol consumption.
Pouring Bigger Drinks
"We found that there is a relationship between how big someone thinks a drink should be and how much alcohol they pour when asked to pour single drinks," said White. "The bigger the definition of a drink, the bigger the drink they pour.""Interestingly, after receiving detailed feedback and instruction on the definition and volume of 'a drink,'" said Tapert, assistant professor of psychiatry at the VA San Diego Healthcare System and the University of California at San Diego. "the college students became more accurate in determining drink size and consequently reported that they typically consumed a larger number of beverages than they had previously reported. This suggests that college students, and perhaps other groups, may underreport the amount of alcohol they consume, but that education about the definition of 'a drink' can improve the accuracy of self-reported drinking."
Education Needed on Drink Size
"If we tell students that binge drinking – four drinks for females and five for males at a time – is dangerous and we want them to stay under this limit, then we absolutely must do a better job of teaching them what a drink is," added White.White suggested that college itself would be a good place to start, either during freshman orientation or via a school-wide e-mail. He also suggested that manufacturers of alcoholic beverages step up to the proverbial plate.
Serving Size on Containers
"Why they are not required to place serving-size information on their containers, or why they do not do so voluntarily, is way beyond my understanding," he said. "If you buy grape juice in a grocery store, all you have to do is look at the label to find out how many ounces are in a serving and how many servings are in the entire container. If that information is on grape juice, then why isn't it on wine, which is just fermented grape juice?"Both Tapert and White noted the implications of these findings for how alcohol researchers assess drinking behavior. "The data simply suggest that we shouldn't take students' answers to questions about how much they drink at face value until we are certain that all students are being taught how to better define standard drinks."
