Abstract
Alcohol consumption is described in terms of both quantity and frequency of alcohol use. This article describes present knowledge of alcohol use in young adults, complex factors that influence alcohol use and binge drinking, nutrition and body weight consequences of alcohol use, and interventions that may decrease alcohol use. Young adults have the highest prevalence of infrequent, high-quantity alcohol consumption in any age group, placing them at an increased risk for weight gain, overweight, and obesity. Lifestyle medicine practitioners can have a positive impact by sharing 4 key recommendations about alcohol use: (a) alcohol provides calories but no essential nutrients;(b)if alcohol is consumed, it should be consumed in moderation—up to one drink per day for women and two drinks per day for men;(c) moderate-level alcohol consumption is associated with the lowest risk of obesity (d) moderate-level alcohol consumption, when consumed in a binge-drinking pattern, is not protective against obesity.
A 2011 cross-national review found that young North Americans and women are drinking less frequently but they are consuming more alcohol per drinking episode now than they were before World War II.
Alcohol use has been studied from diverse perspectives around the world.1,2 A 2011 cross-national review found that young North Americans and women are drinking less frequently but they are consuming more alcohol per drinking episode now than they were before World War II. 2 This article focuses on the present knowledge of alcohol use in young adults, the complex factors that influence alcohol use and binge drinking, the nutrition and body weight consequences of alcohol use, and interventions that may decrease young adult alcohol use. The 4 takeaway messages of this article are the following: (a) alcohol provides calories but no essential nutrients; (b) if alcohol is consumed, it should be consumed in moderation—up to 1 drink per day for women and 2 drinks per day for men; (c) moderate-level alcohol consumption is associated with the lowest risk of obesity; and (d) moderate-level alcohol consumption, when consumed in a binge-drinking pattern, is not protective against obesity.
Defining Alcohol Consumption
Alcohol consumption can be described in terms of the quantity and/or frequency with which alcohol is used. There are 4 commonly used terms to express the quantity of alcohol consumed: abstinence (0-0.25 drinks/day for men and women), low or moderate drinking (0.25-4 drinks/day for men and 0.25-2 drinks/day for women), hazardous drinking (4-6 drinks/day for men and 2-4 drinks/day for women), and harmful drinking (more than 6 drinks/day for men and more than 4 drinks/day for women). 3 Binge drinking, as defined by the National Institute on Alcohol Abuse and Alcoholism, refers to patterns of drinking alcohol that bring blood alcohol concentration ≥0.08%. For typical adults, this pattern corresponds to consuming 5 or more drinks for men, or 4 or more drinks for women, in about 2 hours. 4 However, binge drinking is commonly used to convey a pattern of alcohol use in which alcohol is used infrequently or frequently in high quantities with the goal of getting drunk. 5 Heavy episodic drinking is the term for binge drinking used in some literature to avoid confusion between binge drinking and a binge on alcohol or other drugs defined as an extended bout of substance use (alcohol or other drugs) of at least 2 days during which time all other activities are neglected. 6 Review of the literature reveals that the definition of binge drinking varies from study to study.
Alcohol Use in Young Adults
Among American young adults (18-24 years), there were 5534 alcohol-related unintentional injury deaths per 100 000 in 2005—greater than 40% of all unintentional injury deaths of young adult Americans that year. 7 When the focus was narrowed to only college students, there were 1825 alcohol-related injury deaths per 100 000 in 2005. 7 In 2005, 33% of young adults who died from alcohol-related unintentional injury deaths were college students. 7
Mundt et al found that the frequency of binge drinking episodes in the past 28 days was more strongly associated with alcohol-related injury risk in the past 6 months than the quantity of alcohol consumed during a binge. 8 Specifically, binge drinking, 11 or more times in 28 days, increased male college students’ chance of alcohol-related injury in the past 6 months by 33%, when compared with males who binged 1 or 2 times in the past 28 days. 8 A similar pattern was seen in female college students, but with a rise in alcohol-related injury risk with 1 or 2 days of binge drinking compared with none. 8 The finding that frequency of binge drinking in college students was the key measure for alcohol-related injury risk rather than quantity and frequency of alcohol consumption was supported by a review of the literature. 9 In a prospective study, Mundt et al showed that the number of alcohol-induced memory blackouts predicted alcohol-related injury over 2 years. 10 Other significant covariates included prior alcohol-related injury, being underage (18-20 years), sensation-seeking personality, and binge drinking. 10 Mundt et al also found that underage (18-20 years) college students reported the most alcohol-induced memory blackouts, with no significant differences between males and females. 10
Alcohol exerts its influence on health through an interaction between an individual’s genes and environment. 1 Young adults, ages 18 to 25 years, have the highest rates of alcohol dependence in the United States. 1 For all ages, men reported binge drinking 5 times a month (frequency) and consuming 9 drinks per occasion (quantity), whereas women reported binge drinking 3.2 times a month and consuming 5.9 drinks per occasion. 11 Four Harvard School of Public Health College Alcohol Study surveys revealed that the majority of college students who choose to drink alcohol do so “to get drunk,” resulting in a binge-drinking pattern of alcohol consumption. 12 It is clear that alcohol has detrimental effects on the health of college students in the form of mortality, morbidity, injury risk, and memory blackouts.
Binge Drinking in Young Adults
Young adults have the highest prevalence of binge drinking in any age group. 9 The Behavior Risk Factor Surveillance Survey (BRFSS) defines binge drinking as consuming 4 or more alcoholic drinks per occasion for women and 5 or more for men during the past 30 days. 13 Figure 1 is a map of the United States depicting the percentage of the adult population (>18 years) in each state that self-reported binge drinking from 2009 BRFSS landline phone respondents. 13 The prevalence of binge drinking ranged from 6.8% in Tennessee to 23.9% in Wisconsin. 13 The 2009 BRFSS revealed that 25% percent of US young adults (18-24 years) self-report that they are binge drinkers. 13 Historically, the BRFSS has been limited by the fact that it only surveyed landline phone numbers; it was believed that due to this there was underreporting of the prevalence of risk factors in the young adult age group (18-24 years), many of whom do not have landline phones. 13 In the 2009 survey, the BRFSS addressed this limitation by sampling cell phone numbers. 13 The suspected limitation was confirmed when the 2009 BRFSS 18- to 24-year-old cell phone respondents reported higher rates of binge drinking than 18- to 24-year-old landline respondents, 35.4% versus 25.6%. 13 In 2012, the Centers for Disease Control and Prevention reported that binge drinking (consuming 5 or more drinks in a sitting for men and 4 or more drinks in a sitting for women) was the highest among 18- to 24-year-olds in terms of quantity (mean of 9.3 drinks per drinking occasion) and prevalence (28.2% of young adult respondents). 11
Prevalence of Binge Drinking Among Adults Surveyed by Landline Telephones by State—2009 Behavioral Risk Factor Surveillance System, United States (From Centers for Disease Control and Prevention 13 ).
In 4 nationwide surveys between 1993 and 2001, conducted by Harvard, college students decreased moderate drinking and increased rates of choosing not to drink and binge drinking. 14 Between 1998 and 2005, college students self-reported more binge drinking than age-matched peers who were not attending college, 7 suggesting that there is something unique about the college environment that promotes binge drinking. The fall 2009 American College Health Association–National College Health Assessment II (ACHA-NCHA II) found that the mean quantity of alcoholic drinks that college students self-reported consuming the last time they “partied” was 5 drinks (6 for males and 4 for females); 29.7% of college students (36.4% males and 25.9% females) consumed 5 or more alcoholic beverages in a sitting at least once in the past 2 weeks, meeting the ACHA criterion for binge drinking. 15 According to the College Health Intervention Project Study (CHIPS), which was conducted at 4 US institutions and 1 Canadian institution that sampled college students 18 years and older (79% 18-21 years and 21% ≥25 years), males drank an average of 6 drinks/day (quantity) and 10 days/month (frequency), totaling 60 drinks in 28 days, and females drank an average of 4 drinks/day and 9 days/month, totaling 36 drinks in 28 days. 8 The emerging alcohol consumption pattern of North American college students’ is increasing heavy episodic drinking2,8,14 and decreasing light drinking.8,14 This is concerning since it is well known that consuming alcohol in moderation yields the greatest health benefits.16-19
Roughly half of all college students are using alcohol at levels that place them at risk for alcohol-related problems. 20 Fifty-five percent of students visiting university health services for other reasons reported binge drinking in the past 30 days. 20 Binge drinking rates were highest among 18- to 20-year-old male students, with 30% reporting 5 or more heavy drinking episodes (5 or more drinks for men and 4 or more drinks for women) in the past 30 days, compared with 14% of females in the same age group. 20
Alcohol, Body Weight, and Nutrition
There is no consensus on the effect of alcohol consumption on weight status to date. 21 Studies have shown that consuming alcohol on top of a diet that meets an individual’s caloric needs leads to weight gain,22,23 particularly abdominal adiposity.24,25 Conversely, a 12.9-year prospective cohort study of healthy, normal weight, middle-aged women from the United States found that the amount of weight gained decreased as alcohol intake increased. 26 However, the strength of this association decreased with age over 3 age groups: 38.9 to 50 years, 50 to 59 years, and 60 years or older. 26
A 2011 review of the relationship between alcohol consumption and body weight found that for those who were already overweight or obese, as alcohol consumption increased, weight increased. 21 Overall, the research also suggested that heavy drinkers (≥4 drinks/day) experience weight gain proportionate to their alcohol consumption, whereas low or moderate drinkers (1-2 drinks/day) are protected from weight gain. 21 Recent review articles on the subject agree that alcohol’s role as a predictor of weight status remains inconsistent, but the J-shaped curve hypothesis is supported by several recent studies.16,17,21,27 That is, moderate-level alcohol consumption (an average of 1-2 drinks a day for women and 2-3 drinks a day for men, as recommended by the Dietary Guidelines for Americans 2010, is associated with the lowest risk of obesity. 27
Yeomans found that moderate alcohol consumption (1-2 drinks/day for women and 2-3 drinks/day for men) when consumed in a binge-drinking pattern (7-14 drinks/week, but 4-7 drinks over 2-3 occasions for women; and 14-21 drinks/week, but 7-10 drinks over 2-3 occasions for men) was no longer protective against obesity. 27 Binge drinkers are shown to be more likely to be overweight or obese when consuming the same total amount of alcohol (7 drinks/week) than quantity-matched individuals with more drinking sessions (1 drink/day with 7 drinking sessions vs 7 drinks in 1 drinking session). 27 These findings are supported by another review 17 and clearly place college students, the majority of whom report a binge-drinking pattern of alcohol consumption, 12 at an increased risk for weight gain, overweight, and obesity.
On the other hand, the literature is less clear on the health effects of alcohol consumption when alcohol use is examined as part of a broader dietary pattern. Alcohol provides 7 kcal/g and no essential nutrients, making alcohol a source of empty calories. 27 Paradoxically, alcohol features prominently in the Mediterranean diet pattern as well as the “French paradox,” in which alcohol consumption is encouraged due to its health benefits, such as decreased risk of ischemic stroke, type 2 diabetes mellitus, peripheral vascular disease, and especially risk of coronary heart disease.16-19 The Dietary Guidelines for Americans 2010 recommendation on alcohol consumption is, “If alcohol is consumed, it should be consumed in moderation—up to one drink per day for women and two drinks per day for men—and only by adults of legal drinking age.” 28 This guidance specifies “moderation” based on the pattern of alcohol consumption that is associated with the lowest cardiovascular disease risk and all-cause mortality.16-19
When Zagorsky and Smith examined freshmen weight gain using the National Longitudinal Survey of Youth, 1997, they found that freshmen gained 2.5 to 3.5 lb. 29 The 3-pound weight gain seen in college freshmen persists each year of college, leading to an average weight gain of 8.9 lb for females and 13.4 lb for males from enrollment to graduation. 29 When Kasparek et al looked at only male and female college freshmen who self-reported weight gain, the average freshmen weight gain rose to 7.1 lb from 2.5 lb in the total sample. 30 Kasparek et al examined the relationship of physical activity, fruit and vegetable consumption, and alcohol intake with weight gain in college freshmen over 6 months. 30 This group found that fruit and vegetable consumption decreased significantly, whereas alcohol consumption increased significantly, and that no significant difference was found regarding physical activity. 30
In 2007, Adams and Rini published predictor variables for weight gain in first-year college students. Compared with those who did not gain weight, females who gained weight ate more low-fiber foods, consumed alcohol, had maladaptive coping practices, consumed caffeine, and were less likely to eat cruciferous vegetables, refrain from eating high-cholesterol foods, and to be stress-free. 31 These results showed that alcohol, as part of dietary pattern, was associated with weight gain in female college students. 31 Another study showed that increasing alcohol intake was associated with poorer diet quality for both men and women. 32 The association was shown when alcohol intake was represented by quantity and frequency of alcohol consumed. 32
Individual Counseling and Educational Interventions
An individual educational intervention model that is effective in 18- to 30-year-old individuals is two 15-minute counseling sessions with primary care physicians. 33 Grossberg found that 15-minute counseling sessions, 4 weeks apart, resulted in significant reductions in the following measures of high-risk drinking: number of subjects who report drinking 3 or more drinks per day, average 7-day alcohol use, number of subjects who report drinking 6 or more drinks per occasion, and number of reported binge-drinking episodes in the previous 30 days. 33 The CHIPS was delivered by students’ primary care physicians in the form of two 15-minute sessions integrated into standard care for the experimental group. 34 This approach takes advantage of an opportunity for physicians to motivate students to modify their alcohol use while they are seeking treatment for other health concerns. 34 At 12-month follow-up, Fleming et al found a statistically significant reduction in the number of drinks consumed over the past 28 days and fewer alcohol-related problems in the experimental group. 34 However, the brief intervention was not successful in decreasing the frequency of binge drinking. 34 While patients in their 30s or 40s displayed a stronger response to brief physician interventions, the technique is also effective in the young adult age group and the college clinical setting. 34
Conclusion
Alcohol consumption is described in terms of both the quantity and frequency of alcohol use. Frequent, moderate-quantity alcohol consumption (an average of 1 drink a day for women and 2 drinks a day for men), as recommended by the Dietary Guidelines for Americans 2010, is associated with the lowest risk of obesity. Young adults have the highest prevalence of infrequent, high-quantity alcohol consumption in any age group, placing them at an increased risk for weight gain, overweight, and obesity. However, brief physician counseling interventions are effective in the young adults. Thus, lifestyle medicine practitioners can have a positive impact by sharing 4 key recommendations about alcohol use with young adults: (a) alcohol provides calories but no essential nutrients; (b) if alcohol is consumed, it should be consumed in moderation—up to 1 drink per day for women and 2 drinks per day for men; (c) moderate-level alcohol consumption is associated with the lowest risk of obesity; (d) moderate-level alcohol consumption, when consumed in a binge-drinking pattern, is not protective against obesity.