Normal-weight women who drank 5 to 30 grams of alcohol daily gained less weight and had a lower risk of becoming overweight or obese than either teetotalers or those who drank too much, according to a report in the March 8 Archives of Internal Medicine.
How much is that? A 12-ounce light beer contains about 11 grams of alcohol, while 5 ounces of red wine contains 15 to 16 grams and a 1.5 ounce shot of 80-proof whiskey contains about 14 grams of alcohol.
Researchers conducted an analysis of data from the prospective cohort Women's Health Study of 19,220 women over age 38 who were disease-free and had a normal body mass index (BMI) at the outset.
They reported their weight and alcohol consumption on a questionnaire at that time, and reported their weight again on eight annual follow-up questionnaires.
The women were followed for an average of 12.9 years. During that time, 41.3 percent of the women became overweight or obese, while 3.8 percent became obese.
Average weight gain was 3.63 kg -- about 8 pounds -- for those who didn't drink, compared with 1.55 kg -- about 3.5 pounds -- for moderate drinkers.
The researchers found an inverse relationship between alcohol consumption and subsequent weight gain. "Weight gain was largest for women who did not consume alcohol and then monotonously decreased with increasing total alcohol intake," they wrote.