Moderate female drinkers are less likely to gain weight than those who drink mineral water, according to a new study, Women drinkers also have a lower risk of obesity than teetotallers. The research suggests that a calorie from alcohol has less impact on weight than a calorie from other foods.

It is thought that in regular drinkers, the liver develops a separate metabolic pathway to break down alcohol, with surplus energy turned into heat, not fat. The findings come from a 13-year study of 19,220 American women conducted by Lu Wang, a medical instructor at Bringham and Women's hospital, Boston. Wang questioned the women about their drinking habits, 38% of whom were non-drinkers.

Over the 13 years, the non-drinkers gained the most weight, while the women's overall weight gain decreased as alcohol intake increased. Red wine was found to cause the lowest weight gain amongst alcohol types, while beer and spirits caused the greatest.

The report, published in the Archives of Internal Medicine, seems to confirm that there is no clear connection between alcohol consumption and weight gain, contradicting dietary dogma that suggests weight gain is linked to alcohol intake.

Catherine Collins, a spokesperson for the British Dietetic Association said: 'It's a question of 'what's your poison?' If women were drinking more than two units a day of course they would put on weight'. 'What the survey shows is that moderation is the key to a healthy lifestyle', Collins added.