A Calorie Isn't Just a Calorie

The amount of calories (kcal) found in a food is determined as follows:

  • Carbohydrate = 4 kcal/gram
  • Protein = 4 kcal/gram
  • Fat = 9 kcal/gram
  • Alcohol = 7 kcal/gram

By definition calories are all the same in respect to the amount of energy they provide. These are the hard facts and no one has yet to say otherwise. I'm sure we've all heard that to lose or gain a pound we would need to shed or take in 3,500 kcal's. If all calories are created equal then this idea makes perfect sense. Which is why in practice, monitoring the amount you consume will help you maintain a healthy weight. Yet the issue is more complex and this might explain why certain people have a hard time maintaining a healthy weight despite minimizing their caloric intake. 

So where do things begin to get fuzzy?   

When you consider the health and consumption trends in this country in the last 30+ years and just take a closer look at the biochemical processes different food groups go through, it becomes evident that there is more to a calorie than being just a calorie. I am going to focus on the biochemical processes to explain how calories differ.

Recently, I went to "mini-medical school" (courtesy of YouTube), a lecture given by Dr. Robert Lustig on the horror of fructose. It was a lengthy lecture about an hour and a half long, but it opened my eyes to a new way of looking at food. I highly recommend that you take a look for yourself by clicking on this link: Sugar: The Bitter Truth

Dr. Lustig specializes in neuroendocrinology, is a clinical pediatrics professor at the University of California in San Francisco, and is the director of the WATCH (Weight Assessment for Teen and Child Health) Program. With such credentials and experience, I am convinced that it is safe to listen. 

"When God made the poison, it was packaged with the antidote" - Dr. Lustig
He explained that calories, depending on their source, get metabolized differently. Glucose is something that the body needs for energy and every tissue and organ can use glucose. In fact, those with a condition that causes tremendous amounts of glucose to be stored in the liver do not develop liver failure because the body is built to handle and welcome glucose. Fructose doesn't cause the body much harm if eaten with fiber because the fiber limits the absorption of fructose. Fruit is an example of fructose + fiber. Without fiber, however,  fructose is bad news. Unlike glucose, long-term consistent fructose intake contributes to the Metabolic Syndrome*. Also, fructose is metabolized differently. Only the liver can metabolize fructose. Dr. Lustig illustrates this point by showing how if one were to consume the same amount of calories of glucose and fructose, only a small portion of the glucose will be processed by the liver; meanwhile, all of the fructose would end up being processed by the liver. The liver does not process the fructose into energy, instead it stimulates fat making

Therefore, all calories are not created equal. A very small amount of glucose converts to fat and roughly 30% of fructose turns to fat. This is precisely why we need to not only avoid high-fructose corn syrup but also limit if not eradicate the consumption of sugar. The best way to get our sugar is from natural sources that also have the fiber component. That being the case, juice, for example, is a poor beverage selection.

*Metabolic syndrome: a collection of risk factors that when occur together heighten the chances of type 2 diabetes, obesity, lipid problems, hypertension, and cardiovascular disease.

How to minimize or eliminate sugar from the diet:

Make it a habit to read food labels
Drink unsweetened beverages
Avoid processed foods

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