Making printed labels featuring information about calories compulsory could help Britons to eat less, a study has suggested.

Fast food outlets in New York have had to include these on their products since 2007 and research by the city's health department has shown that it encouraged people to consume fewer calories.

One in six people used the printed labels on takeout menus, with many reducing their food intake as a result.

In fact, they bought food with around 100 fewer calories than those who did not bother to look at the information.

Fast food outlets will have to add this information to their products from September 2011.

Dr Susan Jebb from the Human Nutrition Research Centre in Cambridge said: "Calorie labelling will help consumers make an informed choice about what they eat, but sustained improvements in the nation's diet will require a transformation of the food supply too."

However, a recent study by Tufts University found that many eateries in the US are understating the number of calories in their foods.

Denny Bros Ltd, 28 July 2011