Heavy drinking in college can lead to obesity later in life
September 22, 2017
By Kristi Birch
The "freshman 15"—the amount of weight often gained by first-year college students—might affect a person's life for years after college, according to a new study at the University of Kansas Medical Center.
Research by Tera Fazzino, Ph.D., a post-doctoral researcher in the Department of Preventive Medicine and Public Health at the KU Medical Center, shows that heavy episodic drinking during early adulthood increases the risk of transitioning from a healthy weight to overweight or obesity five years later. KU researchers say this is the first study examining the effect of heavy episodic drinking—defined as five or more drinks in one episode for males, four or more for females—in young adulthood on weight over time.
Sixty-five percent of American adults are overweight or obese, and weight gain happens most rapidly during young adulthood. Being overweight is a risk factor for chronic diseases, many different types of cancers, and also premature death. Most research on weight gain in young adults has focused on young people not getting enough exercise and consuming too much fast food and sugary beverages. Those are important factors, but so is alcohol use. Eighteen- to 24-year olds drink more than any other age group, and when they drink, they often have several drinks. Alcohol is highly caloric. When someone has four or five drinks in a single episode, that means the person may consume at least 600 liquid calories in one sitting.
A gem of a find
Fazzino, who has a research background in addiction, particularly in alcohol use disorders in young adults, says that when she started studying obesity as a post-doctoral fellow, she was surprised at the scarcity of data on heavy drinking and weight gain in in this age group. "A lot of data sets used are for all ages, not just looking at young adults, or are only for a single point in time," she said. "It's hard to detect relationships in that type of data."
The idea for the study stems from Fazzino's work in graduate school on the prevention of heavy episodic drinking in college. "I often thought of the caloric aspect of it. But this hasn't really been addressed in alcohol programs," she said. "Then I noticed that in obesity programs, alcohol wasn't targeted, and alcohol use wasn't even reported. The contributions from alcohol have largely been ignored. I thought that was curious, and that's why I wanted to do this study."
Fortunately, Fazzino discovered the National Longitudinal Study of Adolescent to Adult Health, a nationally representative sample of U.S. adolescents surveyed over time about health and risk behaviors from early high school into their thirties. "This data set was a gem of a find," said Fazzino. "It's longitudinal data, and the researchers asked all the target questions to evaluate heavy episodic drinking that are often overlooked, and they also provided measured height and weight data."
The dataset contained data collected at two time periods from 2001-2008. One alcohol drink was defined as 14 grams of pure alcohol, which is equivalent to a 12-ounce beer, a 5-ounce glass of wine, or 1.5 ounces of liquor. Individuals were classified as regular heavy episodic drinkers if they reported that their typical alcohol consumption was four or more drinks for women, or five or more drinks for men, and they drank at least once a month in the previous year. Normal or underweight was defined as a body mass index (BMI) of less than 25; overweight was defined as BMI of 25-29.9, and obese was defined as a BMI of 30 or higher.
Information that should be used
Fazzino found that heavy episodic drinking was associated with a 41 percent increased risk of transitioning from normal weight in people aged 18-26 to overweight in people aged 24-32. Most alarming, the study showed a 36 percent increased risk of transitioning from overweight to obese during that 5-6 year span. In addition, heavy episodic drinking was associated with higher odds of excess weight gain in general. "A lot of times alcohol prevention is focused on short and immediate consequences, but this is something that can stick with them even if their drinking habits change, and it might negatively impact health outcomes later in life," Fazzino said. "Your weight class in young adulthood is highly predictive of your weight class when you are older."
Kimberly Fleming, PhD., Kenneth Sher, Ph.D., Debra Sullivan, Ph.D., and Christie Befort, PhD., are co-authors on the study, which has been published in the August 2017 issue of the American Journal of Preventive Medicine.
Fazzino is now delving into research on the specific reasons alcohol causes the weight gain. In a study she is conducting with the Department of Psychology at the University of Kansas, she is examining other factors. It might not be just that the alcohol contains calories, but that there are also alcohol-related eating habits, such as the snacking that often accompanies an evening of drinking, or perhaps a wee-hours trip to Denny's or the donut shop. She has just finished collecting data for an NIH-funded study on college freshmen and is now analyzing that data. "So far it's pretty interesting," she said. "There are calorie loads for a single night of drinking that are in the thousands just from alcohol."
The researchers also are working to develop smartphone and biosensor technology to assess alcohol use and alcohol-related eating in real time. They expect to submit their findings for publication in a few months.
"Heavy drinking may put people at higher risk for weight gain and transitioning to obesity, Fazzino said. "This is information that should be used in obesity prevention efforts targeted to young adults, and it can be used in alcohol prevention efforts as well."