Counting Calories?
Maybe You Should Be Counting Carbs Instead

How are calories technically defined?

An energetic calorie is the amount of heat it takes to raise 1 gram of water at 1 atmosphere of pressure from the freezing point of 0 degrees Celsius to the boiling point of 100 degrees Celsius -- divided by 100.

Is there a difference between a "nutritional" and an "energetic" calorie?

Yes. A nutritional calorie is equal to a thousand times the value of a scientific one. Thus, the "calories" that you see listed on the side of your cereal box, for instance, are actually energetic "kilocals."

What do we eat that has calories in it?

Proteins, carbohydrates, and fats all do. Alcoholic beverages also have usable biological energy, as do a few other macromolecules, such as polyose, which is typically used as a substitute for sugar.

What do we eat that doesn't?

Tea, coffee, spices, minerals, vitamins, and water don't. However, many commercial variants of these products do in fact have useable biological energy. For instance, even partially sweetened waters can contain dozens of cals.

How many cals are in a gram of fat; a gram of protein; and a gram of carbohydrates?

• Fats: around 9 cals/gram
• Proteins: around 4 cals/gram
• Carbs: around 4 cals/gram

How does the USDA measure food energy?

With an instrument called a calorimeter. Essentially, this burns foods and measures the amount of heat released. Nutritionists then factor in how much heat would be typically lost in digestion (and thus unavailable for the body as chemical energy).

;Are all cals created equal?

This is a crucial question. According to the conventional wisdom, the answer is yes. But maybe we need to reconsider that assumption.

Why?

Because our bodies digest proteins, fats, carbohydrates, and other food sources differently. We transform carbohydrates, for instance, into simple sugars like glucose; whereas we break fats down into triglycerides and fatty acids.

So what?

The prevailing view that the body metabolizes all energy sources the same way, regardless of their biochemistry or when/how/with what they're ingested is clearly wrong. And it leads people to make overly simplistic and wrong conclusions about why we fatten and how we can lose weight.

But isn't weight loss all about counting cals?

Not necessarily. Just because we've had this idea beaten into us since childhood doesn't make it true. Consider, for instance, the curious case of the disease called progressive lipodystrophy. This is a frightening condition in which individuals can simultaneously fatten and become emaciated. For instance, a subject might show emaciation in the trunk and torso and obesity in the legs and feet.

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