BAKERSFIELD, Calif. -- Dieters are often advised to avoid alcoholic beverages because they provide extra calories with no particular nutritional benefit. A 12 ounce beer, for example, carries about 150 calories and cocktails with added fruit juice can total even more.

But light drinkers may not need to worry so much about gaining weight, according to new research.

Doctors from the Harvard School of Public Health tracked weight gain and alcohol use in more than 19,000 middle-aged women. They found that women who drank the equivalent of 1 to 2 glasses of wine per day were less likely to become overweight or obese than those who abstained from alcohol.

On average, light-to-moderate drinkers gained around 5 and a half pounds over 12 years -- compared to 8 pounds for non-drinkers. The type of alcohol did not matter -- beer, wine or liquor all were associated with lower weight gain.

But alcohol can have negative impacts on health too -- including addiction problems and increased cancer risk -- so experts did not recommend drinking as a weight-loss strategy.