jeudi 5 septembre 2013

Uselessness Of A Calorie Counter

By Dr. Mary Butler


Ignore your calorie counter. And ignore the calorie count on food labels. Counting calories is a mindless strategy for choosing what you eat. Why? First off, understand that a calorie is a unit of heat. It isn't useful for metabolism. Once a calorie is released as heat, there is no putting it back.

Scientists define a calorie simply as the amount of heat necessary to raise a milliliter (cubic centimeter) of water one degree Celsius, at sea level and at room temperature. Consuming calories is like saying that you can eat heat.

Many experts who should know better wrongly equate food calories to metabolism. This overly simplified claim is the basis for saying that food provides metabolic energy in the form of heat. Wrong!

Since you now know that calories are merely heat, you can understand why the only thing they do is effect temperature. The help with maintaining body temperature, not directly with metabolism.

Do you realize how food calories are measured? We completely incinerate the food in a lab instrument called a bomb calorimeter. When a substance is completely burned up, until nothing except its charred remains are left, it has lost all the calories that it contained. When this is done in a bomb calorimeter, the amount of heat that is released is expressed as calories.

In a bomb calorimeter, carbohydrates yield 4 calories per gram, proteins yield 4 calories per gram, and fats yield 9 calories per gram. However, it is nonsense to suggest that these food groups provide you with anywhere near the amount of heat that they yield in a bomb calorimeter. You can see why the whole business of keeping track of food calories, as measured in a bomb calorimeter, for weight loss is so misleading as to be ridiculous.

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.

For one thing, you could never harvest all the energy out of food. You might get 10 or 20 percent of it, certainly no more than 30 percent. Sometimes you won't get any calories at all. Using a calorie counter tells you absolutely nothing about what your metabolism will do with different foods.

Consider this comparison: starch vs. cellulose. Cellulose is indigestible fiber, whereas starch is a source of food energy for humans. However, gram for gram, they both yield the same exact number of calories in a bomb calorimeter.

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.

Comparing the metabolism of food to how a calorimeter (furnace) works is not nearly as meaningful as understanding the fate of different foods when they are digested. It is especially meaningful to understand how different cells and tissues, such as fat vs. muscle, are impacted by different foods.

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, you will be clearer about the uselessness of calorie counts for losing weight once you grasp the difference between calories and metabolism. Chew on that notion for a while (pardon the pun). This is the clarity of thinking that will guide you to a lifetime of success in whatever weight management or fitness program that you pursue.




About the Author:



Aucun commentaire:

Enregistrer un commentaire