Women who are light or moderate alcohol drinkers gain less weight and are less likely to become overweight than non-drinkers, a new study said.

Dr. Liz Wang of Brigham and Women's Hospital studied more than 19,000 women over age 39 who had a normal BMI at the start of a the program. Thirty-eight percent did not drink at all, and the others were classified based on how much they drank.

They were followed for an average of 13 years.

The researchers found that those who did not drink alcohol at all gained the most weight. As alcohol consumption rose, the amount of weight gained dropped.

Women who had a moderate amount each day were 30 percent less likely to become overweight or obese than those who do not drink.

The authors said that the results were similar whether a woman drank red wine, white wine, beer or liquor. But red wine had the strongest effect.

The study appears in the March 8 issue of Archives of Internal Medicine.