Discussion about the negative effects of alcohol often focuses on liver and brain damage, but calorie content is rarely mentioned.
The World Cancer Research Fund (WCRF) warned earlier this year that alcohol accounts for nearly 10 per cent of total calorie intake among drinkers.
One gram of ... carbohydrate and protein give us four calories, alcohol gives us seven and fat gives us nine
"The calories in alcoholic drinks account for a significant proportion of a drinker's calorie consumption, while providing little, if any, nutritional benefit," says Kate Mendoza, head of health information at WCRF. "Cutting down on drinking can have a big effect on weight loss or maintaining a healthy weight.
"Recent reports have shown that people are unaware of calories in drinks and don't include them when calculating their daily consumption. This is important from a cancer perspective because, after smoking, being overweight or obese is the biggest risk factor."
Alcohol is second only to fat in the number of calories per gram. Karen Chong, a registered dietitian with Matilda International Hospital, explains: "In our diet, there are four things that we get calories from: carbohydrate, protein, fat and alcohol. For one gram of each of those, carbohydrate and protein give us four calories, alcohol gives us seven and fat gives us nine."
There may be two reasons why calories are often overlooked when it comes to alcohol, says Dr Goh Ping Ping, a cardiologist at the Cardiac Specialist Centre of Mouth Elizabeth Medical Centre in Singapore.
"Although we know the calorie content of alcohol, the actual calories consumed from a drink depends on its alcohol percentage," she says. "There are many types of alcoholic beverage, each with a different alcohol content from very high, such as in spirits, to lower, such as in beer. Hence it may be difficult to tell how many calories are being consumed.