“Scientists have shown that too little sleep can disrupt our hunger and satiety mechanisms, leading to increased appetite and snacking during the day,” says the nutritionist Dominique Ludwig. “We all know that if we feel tired we want the quick fixes that are usually rich in sugars or refined carbohydrates and they are bad news for the waistline.”

Their lack of sleep led to a 9 per cent increase in total belly fat and an 11 per cent increase in harmful abdominal visceral fat, and catching up with recovery sleep and naps did not reverse these gains, at least in the short term. “Establishing a good sleep routine with regular bedtimes and not eating for at least two to three hours before bed are excellent strategies for fighting belly fat,” Ludwig says.

“Remember that alcohol is a carbohydrate with around seven calories per gram,” Ludwig says. “A pint of beer contains about 215 calories, as many as are in a chocolate bar, and we should always consider it as extra food in our diets.”