Conventional wisdom holds that drinking alcohol is linked to weight gain. Intuitively, it makes sense: Nightly beers and weekend cocktails are sources of empty calories. A new health warning label in Ireland on alcoholic beverages will even highlight, among other things, the calorie count.
But the research doesn’t confirm that indulging in these pleasures will lead to the numbers on the scale inching higher. Not exactly, anyhow.
“It’s not straightforward at all,” says Mackenzie Fong, a dietitian research fellow at Newcastle University in the United Kingdom, of the potential link between drinking and weight. “Or if it is, we certainly haven’t found a way to evaluate that.”
Researchers have tried. Fong was the lead author of a 2021 review of research looking at alcohol consumption and weight gain, which concluded that the link between the two was “uncertain despite no shortage of research over the years.”
A 2015 literature review found that moderate drinking is not associated with weight gain in cohort studies and that randomized-control studies of the question, though mixed, suggest “that moderate intake of alcohol does not lead to weight gain over short follow-up periods.”
One gram of alcohol contains 7.1 calories, and commonly consumed drinks can range from about 100 to 200-plus calories. However, despite your average drink’s seemingly significant calorie count, these beverages don’t contribute to weight gain as much as calorie-counting math suggests they should. The reasons for this are not fully understood.
Take a 2018 study published in the journal Obesity, which examined data from 4,901 overweight or obese individuals with Type 2 diabetes who had participated in a yearslong weight loss program. The program had split participants into two groups. One group received intensive lifestyle interventions, and was told about the number of calories in alcohol. Members of this group were advised that they could decrease drinking as a means of reducing caloric intake. The other group served as a control, and members were invited to three sessions each year focused on diet, physical activity, or social support.
The results were not clear-cut. Looking at data from the end of the first year, researchers found no association between weight and drinking—even among those in the intensive intervention group who reported heavy drinking. But zooming out to year four, there was a small association between weight gain and any drinking in this group. Participants who did not drink lost 5.1 percent of their initial weight on average, which was 2.7 percent more weight than consistent drinkers lost, and 1.6 percent more weight than those who drank at any time during the intervention. However, there was no observed difference in weight based on alcohol consumption in the control group that received minimal weight loss and diet advice.
Since participants weren’t randomized into carefully controlled drinking and nondrinking arms of the study, it’s possible that other factors played a role in the long-term differences in weight observed, wrote the study’s lead author, Ariana M. Chao, a professor at the University of Pennsylvania School of Nursing, in an email. She noted other limitations in her analysis, too. “Participants had type 2 diabetes and overweight/obesity, were 45 to 76 years of age, and the overall depression severity was low, which limits generalizability of findings.” She also noted that “the number of participants with heavy alcohol consumption and the average number of drinks consumed were also low.” She maintains that cutting down on drinking can be helpful for weight loss.
Still, the study suggests that cutting out alcohol isn’t a reliable way to lose weight in the short term, and, over the course of years, may only have a small effect at most.
A 2017 study, also published in Obesity, looked at 24 years’ worth of data from a cohort of 14,971 men. They found that increases in drinking were associated with a small increase in weight over the course of four years—0.3 pounds per drink consumed in a typical day (so if you had three beers a day, this might lead to about a single pound of weight gain over four years). Differences based on drink type were not statistically significant, but liquor intake was associated with more weight gain and wine and light beer were not significantly associated with weight change. But don’t take that as a reason to avoid whiskey, or really any alcohol, for that matter. The authors concluded that “increased alcohol consumption was associated with minor reported weight gain at levels unlikely to be clinically meaningful.” You’d be hard-pressed to pin the existence of beer bellies on beer.
“I think in the long run, people who drink more do gain a little bit of weight and people who give up some [drinking] over time do lose a little bit of weight,” says Eric Rimm, a co-author of the study and a professor of epidemiology and nutrition at Harvard’s T.H. Chan School of Public Health. “But it’s very small.”
Interestingly, that small weight difference might be due to factors other than the actual calories in alcohol. The authors of the 2017 study also tried to control for variables beyond alcohol consumption that may have played a role. They found that changes in drinking were associated with changes in time spent watching TV, and that as people drank, they also consumed more calories from other sources.
For some people, alcohol may affect their decision-making to the point where it does actually affect their weight. A study published in 2016 in the journal Appetite found that drinking was “unrelated to weight change” overall in the 283 overweight and obese adults who had participated in a one-year, 26-session behavioral weight loss treatment. “But there was a really specific group of participants for which alcohol reduction did matter for weight loss, and that was participants who scored high on our measure of behavioral impulsivity,” says Colleen Kase, the lead author of the study and a professor of psychology at Stockton University. High-impulsivity individuals who substantially decreased their alcohol intake over the course of the treatment lost approximately 16 percent of their original weight, on average, 12 percentage points more than high-impulsivity individuals who did not significantly reduce their alcohol intake. “So it seems like for those highly impulsive participants, reducing their alcohol intake really does benefit their weight loss over time,” she says.
Other research has suggested a link between drinking and increased calorie consumption, though like everything around drinking and weight research, the link is uncertain. Fong’s review examined several studies that randomly assigned participants to drinking or nondrinking groups during short experimental sessions. These studies found that people who drank alcohol tended to eat more afterward than those who drank nonalcoholic beverages. For instance, in one randomized control study included in Fong’s review, 60 female college students were randomly assigned to two groups. One group was given an alcoholic beverage while the other was given a placebo drink they were told contained alcohol. They were also offered cookies—which the group that received alcohol consumed more of. But the real-world implications of this and other similar studies are hard to assess, says Fong. In some instances, the difference between calories consumed was quite small. Plus, “we don’t drink in laboratory settings,” Fong says. What happens after you have a drink at a bar or on your couch isn’t carefully controlled.
Before Fong conducted research into this topic, she would advise those she worked with as a dietitian to cut calories by moderating their alcohol intake. “Would I do that now, having done all this work on the evidence? I think I still would because it still could have other benefits, with a bonus being weight loss,” she says.
As for why the calories in alcohol don’t seem to quickly add up to a lot of extra weight, it’s a little bit of a mystery. “It’s nuanced and it’s complex, because we don’t live in an environment where you just take each food item and inject it and it has no impact on anything else that happened,” says Rimm. Drinking can raise your heart rate and speed up your metabolism, Rimm explains, offsetting some of the calories consumed in the drink. Though people may consume more calories along with alcohol, it’s also possible they’re burning some of those collective calories off later, or eating less at another point in the day, which can lower any weight gain.
Diet culture has long vilified alcohol as a major contributor to weight gain. This is one of the reasons sales of spiked seltzers, with their relatively low calorie counts, have increased so dramatically in recent years. But while alcohol is not exactly a health elixir, when it comes to its impact on weight, it’s not a guilty pleasure we should feel all that guilty about.