A study published by the New Scientist, 15th July 2009, magazine isue 2717, suggests that the long held belief of the way we calculate calories in foods and the information displayed by food labels might be wrong.

A select band of scientists and researchers argue that calorie estimates on food labels are based on flawed and outdated science that provide misleading information on how much energy your body will actually get from a food. They suggest that some food labels might even underestimate the calorie content of some foods by as much as 25 percent - enough to foil any weight loss or calorie controlled diet.

For years we have understood that, roughly speaking, protein and carbohydrates contain 4 calories per gram and fat 9 calories per gram and that if you eat less calories than you burn via activity you will lose weight. To a certain extent this is true. However, some researchers are showing that if food labels are incorrect, then this calorie deficit needed for weight loss will not occur.

Energy used in mastication and digestion

The research underpinning these new ideas show that some foods and their energy are digested at different rates due to chewing and the chemical breakdown of food in the mouth and gut. This means that the energy released in foods will be different, even if the food label in terms of total calories looks very similar.

Small values can equal big changes

The research team behind the study highlight the issue by suggesting that a small increase of only 20 kcal a day would equal an increaseof roughly a kilogram of fat per year!

As such, with the world\'s population getting fatter each year, the scientists behind this theory suggest we should look to change the way we view food labels from now on.