dimanche 25 août 2013

Counter Counter Is Useless

By Dr. Eva Reynosa


Toss out your calorie counter. Pay no attention to the calorie count on food labels. Counting calories is a useless and simple-minded way to decide what you eat. How come? Firstly, a calorie is a unit of heat. Heat does not directly guide metabolism. When caloric heat is released, nothing will put it back.

A calorie is simply how much heat it takes to raise a cubic centimeter (milliliter) of water by one degree Celsius, starting at room temperature and at sea level. Saying that you can eat calories is like saying that you can eat heat.

Health professionals, trainers, nutritionists, and many other experts who ought to know better, wrongly equate food calories to metabolism. This is based on simple-minded reasoning that says calories from food provide you with energy. This is incorrect!

Now that you know what calories really are (i.e, heat), you can understand that the only thing they can do is effect temperature. They are important for maintaining body temperature, but that is all.

It is helpful to know how food calories are really measured. It is done by completely incinerating the food in an instrument called a bomb calorimeter. In so doing, when only the charred remains are left, it has lost whatever calories it originally contained. The bomb calorimeter measures the amount of heat lost and expresses them as calories released.

The total heat that can be released from food in a bomb calorimeter is well-known for the three main food groups: 4 calories per gram of carbohydrate or protein and 9 calories per gram of fat. However, these numbers reflect only the maximum caloric yield in a bomb calorimeter. This number has nothing to do with what your body gets from food. This is why the maximum caloric potential of foods is, indeed, a nearly useless criterion when it comes to weight loss.

If your body behaved like a bomb calorimeter, then the calorie count of foods, such as those on food nutrition labels, would have more meaning. Your metabolism, however, has nothing to do with what happens in a bomb calorimeter.

You can never, ever get all the energy out of food. At the most you might get 10 to 20 percent of the potential energy through your fuel-harvesting metabolism. You will certainly never get more than 30 percent. Sometimes you won't get any calories at all. Using a calorie counter tells you nothing about how your body will metabolize different types of food.

Consider this: in a calorimeter a gram of starch will yield the exact same number of calories as a gram of cellulose, which is indigestible fiber. As you already know, starch is a source of food calories for people. In contrast, cellulose is not.

Likewise, a calorimeter will derive the same number of calories from equivalent amounts of celery and potato, after correcting for water content. Obviously, your body could not possibly do that.

Instead of comparing the metabolism of food to a furnace or calorimeter, it is much more meaningful to talk about what happens to different foods when they are digested, how they get into different kinds of cells (e.g., fat vs. muscle), and what happens to them once they are there.

It may surprise you, for example, to compare two well-known and nearly identical sugars, fructose and glucose. Their caloric yield is exactly the same in a bomb calorimeter. However, glucose goes through the liver into many different tissues, most notably brain and muscle, and fructose never escapes intact from the liver. Counting calories tells you nothing about these two different metabolic fates.

The consequences of the different metabolic fates of glucose vs. fructose are tremendous. Glucose serves your entire body, whereas fructose has to be converted to something else before it can move through your liver. That something else is largely fat. A simple way to look at it is that fructose will make you fat much faster than glucose will. The caloric potential of these two sugars is irrelevant.

By the way, once you understand how misleading the calorie count is for different foods, you will be clearer about why calories have almost nothing to do with being overweight. Now chew on that concept for a while (pardon my pun), because it is the kind of clear thinking that will help you be truly successful in whatever weight management or fitness program that will work for you for a lifetime.




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