New Scientist: The Calorie Delusion

For years I have tried to decipher the calorie enigma. People always talk about calories: how much that burger you're eating has, their daily intake and the most important thing of all - how to reduce the number of calories per food. At this point you should probably concentrate on eating rather than listening.

This article does clarify on how different foods have different amounts of calories as all calorie articles should. However it the text tells us that " calorie estimates on food labels are based on flawed and outdated science and provide misleading information..." Who would have thought? Rejoice all you diet freaks who think that just one calorie over the daily intake will kill them.

"Some food labels may over or underestimate this figure by as much as 25 per cent..." The old way of calculating the energy given to the body by foods was developed in the late 19th century. The cehmist in charge, Wilbur Olin Atwater, calculated the energy content of various foods by burning them and measuring how much heat energy was given out. Atwater then calculated the amount of energy lost as undigested food in faeces, and as chemical energy in the form of urea, ammonia and organic acids found in urine, and then he subtracted these figures from the total. This gave him some approximate values known as the metabolisable energy.

This method has now been proved wrong. Three new factors have now been added to the equation: Texture, Type of Sugar and Cooking. Let's compare two foods: a granola bar and a brownie. The granola proves more difficult to chew so it uses up more energy to be digested than a brownie. The brownie contains refined sugars and flour which is much easier to break down than complex carbohydrates in the granola bar.

Of course we will not be able to use this example for cooking so let's take another one: a steak. If the meat is ground and cooked it will digested easily by the organism unlike raw and intact meat.

From all this we can put in perspective the amount of changes in the nutrition facts of every product. According to The UN Food and Organization (FAO) "the problems and burdens ensuing from such a change would appear to outweigh by far the benefits". Next time you think of having that steak well-done, think again. You might just save a bit of calories.

15 July 2009 by Bijal Trivedi

Magazine issue 2717.