I am not quite sure how this works, but recent research has concluded that women who drink moderate amounts of alcohol tend to gain less weight over time than those who drink no alcohol. This included wine - both red and white, beer or liquor.
Research carried out at Brigham and Women's Hospital in Boston studied the alcohol consumption of over 19,000 women, all starting out at healthy weights. Over the 13 years taken to carry out this study, most women gained weight. However, those who consumed a light to moderate amount of alcohol gained less weight, and were less likely to become overweight or obese. The conclusion drawn from this was that those who drank moderate amounts of alcohol tend to eat less food, particularly carbohydrates.
The reaction to this article which was carried in USA Today appeared to be skeptical, at best, and I have to agree that a glass of wine for me usually means I need to bring out appetizers and snacks (see the picture), so it doesn't often lead me to eating less. I wonder if a similar study has been carried out with men?