Friday April 15, 2016

Discounting Calories

I have decided that I no longer believe in calories. I believe in the definition, of course, thats indisputable. But what does it have to do with food?

A calorie, scientifically speaking, is a unit that is used to measure energy. One calorie is the amount of energy needed to raise the temperature of 1 gram of water by 1 degree Celsius. The Calorie (capital C) used in talking about food is actually a kilocalorie, or 1,000 (little c) calories. A Calorie (kcal) is the amount of energy needed to raise the temperature of 1 kilogram of water 1 degree Celsius.

So, what does heating water have to do with eating, weight gain, weight loss, etc? And how do people determine the Calories on a nutritional label?

Originally, the number of calories in a given food was determined, literally, by burning. The food was placed in "bomb calorimeter" (a sealed container surrounded by water) and then burned. The resulting changed in water temperature was measured, the "degrees C per gram of water" calculation was applied and a number of determined.. I did this experiment in a junior high school science lab.

The calculation is more mathematical (and less combustable) these days. There are no labs where people drop granola bars and hamburgers into calorimeters and burn them to ash.

The Nutrition Labeling and Education Act of 1990 (NLEA) currently dictates what information is presented on food labels. The NLEA requires that the Calorie level placed on a packaged food be calculated from food components. According to the National Data Lab (NDL), most of the calorie values in the USDA and industry food tables are based on an indirect calorie estimation made using the so-called Atwater system. In this system, calories are not determined directly by burning the foods. Instead, the total caloric value is calculated by adding up the calories provided by the energy-containing nutrients: protein, carbohydrate, fat and alcohol. Because carbohydrates contain some fiber that is not digested and utilized by the body, the fiber component is usually subtracted from the total carbohydrate before calculating the calories.

The Atwater system uses the average values of 4 Kcal/g for protein, 4 Kcal/g for carbohydrate, and 9 Kcal/g for fat. Alcohol is calculated at 7 Kcal/g. (These numbers were originally determined by burning and then averaging.)

ref Scientific American.

But back to my original point. I have decided that I no longer believe in calories, at least, not as they have to do with food.

The body is not a bomb calorimeter. It is not a simple water heater. It is a very complex biological system.

I find it very difficult to believe that we can simply burn "average" fats in a lab, determine an average value of 9 Kcal/g, add up the grams of fat (supposedly) in a particular cooked or manufactured food product, do some arithmetic, and determine the amount of energy (or weight gain, etc) an individual will get from that food.

This doesn't feel scientific to me. Not all fats / carbs / proteins are the same. Not all metabolisms are the same. Not all endocrine systems are the same.

If you're not convinced, consider drugs for a moment. Many people, and most doctors, understand that drugs affect different people in different ways. This is the reason why we run clinical drug trials.

Many drugs have side effects. Some side effects are common; some are very rare. NO one disputes the idea that a given person may react differently to a given drug than some random other person.

So why do we believe that food, and "calories", interact with every person's digestive system and metabolism in the same way? We already know that some people have intolerances or allergies to certain foods. Isn't that, really, just a "side effect"?

Gumberries: side effects are rare but may include rash, hives, dizzines, shortness of breath, or anaphylactic shock. Ask your doctor if gumberries are right for you!

I'm going to go with this:

  1. Food is good. We need food to survive.
  2. Some foods are "better" for us than others.
  3. We keep making mistakes and changing our nutritional minds with regard to item #2 on this list. Are fats good for us? Bad for us? Does it depend on the fat? How about carbs? Starch vs sugar? Whole grains? Digestible fiber?

Conclusion: there is no possible way that things are as simple as "calculate average protein/carb/fat content, multiply by an (average) Kcal factor, multiple by total (average) grams, then paste a label on it."

Stop "counting calories" and look at what (and how much) you're actually eating. If you eat a lot of food and don't exercise (a lot), you'll probably gain weight. The number of "calories" doesn't matter if you're deciding between a dozen donuts and a whole turkey!

If you have an actual allergic reaction, intolerance reaction, or disease, avoid certain foods. If you don't have an allergy, intolerance, or disease, ignore the fads. Only a small percentage of the population is actually gluten intolerant. Unless you've been diagnosed by a doctor, your belief that you "feel better" when you cut bread out of your diet is not, actually, an indication of a gluten intolerance!

Everything in moderation.

Too Much

Discounting Calories ( in category Random Thoughts ) - posted at Fri, 15 Apr, 20:41 Pacific | «e»

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