Many diet and exercise programs are based on us “counting calories” and assuming all calories are created equal. This goes back to the 1870’s and the scientific finding of the First Law of Thermodynamics. We learn from Wikipedia, “The first law of thermodynamics states that 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 myth that whatever calories we consume through eating we need to burn through activity otherwise these calories will store as fat and we will gain weight.

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. Basically, this device measures heat flow in water from the burning of a specific substance. The change in temperature in the water is then converted into calories.

So this leads us to the key question. Does our body really 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 or a bagel has 75 calories. Perhaps one bite of a donut or a piece of cake has 75 calories. Could it really be that these 75 calories would have the same impact in your body? I don’t think so and shortly you’ll see why.

Let’s go 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’s 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. I’ve written previously on 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 let’s look at carbohydrates. I’ve written many times that to your 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 do have 4.2 calories per gram, yet 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 really don’t 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’s look at fat. Fat too is used for other functions besides energy. So, in reality, only some of these calories truly count. And here’s 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!

My special thanks to Barry Groves and the Weston Price Foundation for his wonderful presentation sharing these facts.

Bernard Rosen, PhD is a Nutrition Consultant and Educator. He works with individuals, groups, and at corporations to create individualized nutrition and wellness programs. He has offices in Thiensville and Glendale. To learn more or to schedule an appointment, e-mail at, call (262) 389-9907 or go to