Women are often advised to stop drinking to avoid extra calories but a new research suggests that women who regularly consume moderate amounts of alcohol are 30 per cent less likely to gain weight than those who do not drink.

Researchers at Brigham and Women’s hospital in Boston said the women who consumed two to three servings of beer or wine each day were less likely to gain extra pounds as they get older. The 13-year research found that women who did not drink at all gained the most weight.

The findings, reported this week in the Archives of Internal Medicine, are based on a study of 19,220 U.S. women aged 39 and over who had normal body weight at the start of the study. Researchers tracked the women’s drinking habits over 13 years.

About 60 per cent of the women were light or regular drinkers, while about 40 per cent reported drinking no alcohol. Over the course of the study, 41 per cent of the women became overweight or obese. The risk of becoming overweight was almost 30 per cent lower for women who consumed one or two alcohol beverages a day, compared to others who did not drink at all.

The non-drinkers in the study actually gained more weight over time: nine pounds, on average, compared with an average gain of about three pounds among regular moderate drinkers.

The effects were found for beer, red wine, white wine and spirits, although the strongest association was found for red wine. It isn’t clear what accounts for the association, the authors said.

But it is also possible that at least some of the observed link between alcohol and midlife slimness is not direct and has to do, instead, with other things drinking women tend to do, the authors added.

For example, women who drank more alcohol in the study consumed fewer calories from other food sources, particularly carbohydrates.

The women who drank moderately also were more likely to smoke, were more physically active, had lower body mass indexes at the start of the study and had a less healthy diet.

Still, alcohol appeared to influence weight even when researchers controlled for such factors, the authors said.

Regardless of the reason for the link, the research should not translate into advice for women, said Dr James C. Garbutt, a professor of psychiatry at the University of North Carolina’s Bowles Center for Alcohol Studies. “If the message is that by drinking some alcohol you’re going to lose weight, that’s a potentially complicated and dangerous message,” he said.

Other studies have linked consumption of more than one drink a day to an increased risk of breast cancer.

Moderate wine intake, especially red wine, has been found to have some beneficial effects on cardiovascular health in both women and men.

But, Garbutt said, “Alcohol is very much a double-edge sword. For some people, it may have benefit and for others it may have harm.”