What should I eat? How many calories per day should I have? Most diet and exercise programs are based on us “counting calories” and assuming all calories are created equal. What if this were not quite true? If so, where did this concept originate and what implications does it have for us today?

Let us go back to the 1870’s and the latest scientific discovery of its time.  The First Law of Thermodynamics states, “…energy can be transformed, i.e. changed from one form to another, but cannot be created or destroyed. It is usually formulated by stating that the change in the internal energy of a system is equal to the amount of heat supplied to the system, minus the amount of work performed by the system on its surroundings.” This theory was applied to the human being resulting in the belief that the calories consumed through eating need to be burned through activity otherwise these calories will store as fat and cause weight gain.

Also during this period of time scientists were able to assign specific calories to specific foods through the use of a new breakthrough – the bomb calorimeter – a device that measures heat flow in water from the burning of a specific substance. The change in temperature in the water caused by the burning substance is converted into calories.

So this leads us to the key question. Does our body work like a bomb calorimeter? And, are all calories used for energy and therefore the same independent of the food we eat?

As far as a calorimeter goes, I think we can all conclude that our body does not operate that way. But let’s assume that it does. If so, does it treat all calories equally? While you will see many studies supporting the notion that a calorie is a calorie is a calorie let’s take a logical view of this. A hardboiled egg has 75 calories. Approximately one half of a slice of bread has 75 calories. Perhaps one bite of a donut or a very small piece of cake has 75 calories. Could it be possible these 75 calories have the same impact in your body? I don’t think so and shortly you will see why.

Back to the calorimeter for a minute. Here’s what was discovered. Carbohydrates were 4.2 calories per gram and this was rounded down to the familiar 4.0 that we know of today. Proteins were 5.0 but were rounded down to 4.0 due to some perceived inefficiencies of how they burn. Fats were 9.2 also rounded down to 9.0. So, this gives us the numbers that we are all familiar with: 4 calories per gram of carbohydrate and protein and 9 calories per gram of fat. Simple conclusion – eat too much fat and you get fat.

Well, to start with, the figures are wrong! Let us look at fats first. Different fats have different amounts of associated calories depending upon saturation levels. Further studies have shown that polyunsaturated fats have 9.1 calories per gram, animal fats range from 6.5 to 8.0 calories per gram, while cocoa butter (the most saturated of fats) has 5.5 calories per gram. This is significant. Other blog posts promote the benefits of saturated fat, and yet it is these fats that have been so vilified that actually have less calories than the unsaturated oils we have been told are so healthy! The true fact is that the more saturated the fat, the fewer calories.

Now, carbohydrates. As we know to our body carbohydrates equals sugar. All carbohydrates (both “simple” and “complex”) are broken down into simple sugars. To do this the body uses a process called hydrolysis. Basically water is added to a reaction. This causes total mass to increase which actually creates more calories! So, simple sugars really have 4.2 calories per gram and starches (the more complex carbohydrates) have 4.44 calories per gram! Also note that soluble fiber has 2.0 calories per gram. What does this mean? We are getting significantly more calories per gram of carbohydrate than we may think.

Now for the grand finale! This whole theory assumes that all calories we consume are used for energy. This simply is not true. Protein is used for a variety of body building functions. In fact very little protein is used for energy. Therefore, these calories do not count. Think about the Atkins diet. It includes lots of protein, yet people lose weight. In fact they are told to eat as much as they want and still lose weight. Next, let us look at fat. Fat too is used for other functions besides energy. So, in reality, only some of these calories truly count. And here is the important point – it is only carbohydrates where all the calories count! Many studies have shown that the number of calories is insignificant compared to their composition. People can gain or lose weight on calories ranging from 1000 to 4000 calories per day. It is all about how much fat, protein, and carbohydrate were in the diet!

And one last “food for thought.” Consider the following – we are told that if we eat x less calories per day, we will lose y number of pounds over a certain period. Here are the actual numbers. We are told that to lose one pound we need to burn or cut 3500 calories. If we want to lose a pound a week, we can cut 500 calories per day from our diet. Therefore, it is only logical if we maintain that restricted calorie diet, we will eventually melt away to nothing (if you started at 300 pounds this would take six years!). Since we have never seen anyone disappear, we can conclude that it may not work that way.

Bernard Rosen, PhD is a Nutrition Consultant and Educator. He works with individuals, groups, and at corporations to create individualized nutrition and wellness programs. His office is in Coeur d’Alene. To learn more or to schedule an appointment, e-mail at bernie@brwellness.com, call (208) 771-6570 or go to www.brwellness.com.