By Dr. Luke Tolley, PhD in Chemistry (North Carolina) and former professor, Southern Illinois University
We get lots of great comments and questions about the Blue Unicorn bar. Many of these are along the lines of āHow do you make it taste so good?ā and āHow can it only have 120 calories?ā. The answer to the first question is magic, of course, and the second one is what weāll talk about today.
What are calories?
In the simplest terms, calories are a unit of energy. Each calorie represents a certain amount of energy that is in your food. Sounds simple, right? The reality is a little more complicated but not too bad.
To measure calories they originally would basically burn the food and see how much heat it gave off. This does tell you how much energy there is, but the problem is that your body canāt take advantage of all of the sources of energy. For example, this method says that wood has plenty of calories because it burns great. Though the energy is there you canāt take advantage of it, so for humans it basically has zero calories. More modern methods do a much better job of figuring out how much energy you can actually get out of the food, but it can be a bit tricky.
By Dr. Luke Tolley, PhD in Chemistry (North Carolina) and former professor, Southern Illinois University
We get lots of great comments and questions about the Blue Unicorn bar. Many of these are along the lines of āHow do you make it taste so good?ā and āHow can it only have 120 calories?ā. The answer to the first question is magic, of course, and the second one is what weāll talk about today.
What are calories?
In the simplest terms, calories are a unit of energy. Each calorie represents a certain amount of energy that is in your food. Sounds simple, right? The reality is a little more complicated but not too bad.
To measure calories they originally would basically burn the food and see how much heat it gave off. This does tell you how much energy there is, but the problem is that your body canāt take advantage of all of the sources of energy. For example, this method says that wood has plenty of calories because it burns great. Though the energy is there you canāt take advantage of it, so for humans it basically has zero calories. More modern methods do a much better job of figuring out how much energy you can actually get out of the food, but it can be a bit tricky.
Calculating Calories
Calculating the calories in food is pretty simple. This method wonāt give you exact numbers, but it will get you close enough. After I explain the method then Iāll go through the numbers for the Blue Unicorn bar for a real-world example.
Start with the fat. Fat has about 9 calories per gram of fat so you can just multiply the total fat on the label by 9. Donāt worry about how much of it is saturated or not because that doesnāt really matter to calories.
Next go to the protein, which is probably the easiest one. Protein has 4 calories per gram, so you multiply this next and add it to your fat calories.
Carbohydrates are the trickiest. Normal carbs have 4 calories per gram, just like protein, but you usually canāt just multiply the total carbs by 4. Fiber is the first thing that messes up your calculation. You canāt digest fiber, but the bacteria in your gut can digest some of it. This is why most fiber is called a pre-biotic ā it feeds the bacteria. Because of this complicated relationship that you have with your bacteria, many fibers will effectively have 1 - 2 calories per gram. Some of the sweeteners used also have fewer calories than normal carbs. For instance, allulose and erythritol provide less than 0.4 calories per gram. Usually there isnāt enough of these to make much of a difference in your calculations, but they can. Other sugar alcohols still do have the full 4 calories per gram. So hereās what you have to do for carbs. Figure out the net carbs by taking the total and subtracting out the grams of fiber, erythritol, and allulose. Multiply this number by 4. If thereās lots of fiber in the product then go ahead and add the grams of fiber (assuming 1 calorie per gram). These two numbers together will give a good estimate of the carbohydrate calories.
The final category for calories is alcohol, which hasnāt shown up in protein products yet. Iām just including it here for completeness. Pure ethanol has almost as many calories per gram as fat, so you take the grams of alcohol and multiply by 7.
Calculating Blue Unicorn Calories
Hereās how this all works for the Blue Unicorn bar:
4 g fat x 9 calories/g = 36 fat calories
15 g protein x 4 calories/g = 60 protein calories
15 g total carbs - 7 g fiber - 4 g allulose = 4 g net carbs
4 g net carbs x 4 calories/g + 7 g fiber x 1 calorie/g = 16 + 7 = 23 carb calories
Total calories = 36 + 60 + 23 = 119 calories
This method wonāt give you exact numbers because some ingredients will have slightly different calories per gram, but we can get close enough to make sure that the label is accurate. Hopefully now you can understand where the calories in the Blue Unicorn bar come from and the only question remaining is āWhere did they get the magic from?ā
Calculating Calories
Calculating the calories in food is pretty simple. This method wonāt give you exact numbers, but it will get you close enough. After I explain the method then Iāll go through the numbers for the Blue Unicorn bar for a real-world example.
Start with the fat. Fat has about 9 calories per gram of fat so you can just multiply the total fat on the label by 9. Donāt worry about how much of it is saturated or not because that doesnāt really matter to calories.
Next go to the protein, which is probably the easiest one. Protein has 4 calories per gram, so you multiply this next and add it to your fat calories.
Carbohydrates are the trickiest. Normal carbs have 4 calories per gram, just like protein, but you usually canāt just multiply the total carbs by 4. Fiber is the first thing that messes up your calculation. You canāt digest fiber, but the bacteria in your gut can digest some of it. This is why most fiber is called a pre-biotic ā it feeds the bacteria. Because of this complicated relationship that you have with your bacteria, many fibers will effectively have 1 - 2 calories per gram. Some of the sweeteners used also have fewer calories than normal carbs. For instance, allulose and erythritol provide less than 0.4 calories per gram. Usually there isnāt enough of these to make much of a difference in your calculations, but they can. Other sugar alcohols still do have the full 4 calories per gram. So hereās what you have to do for carbs. Figure out the net carbs by taking the total and subtracting out the grams of fiber, erythritol, and allulose. Multiply this number by 4. If thereās lots of fiber in the product then go ahead and add the grams of fiber (assuming 1 calorie per gram). These two numbers together will give a good estimate of the carbohydrate calories.
The final category for calories is alcohol, which hasnāt shown up in protein products yet. Iām just including it here for completeness. Pure ethanol has almost as many calories per gram as fat, so you take the grams of alcohol and multiply by 7.
Calculating Blue Unicorn Calories
Hereās how this all works for the Blue Unicorn bar:
4 g fat x 9 calories/g = 36 fat calories15 g protein x 4 calories/g = 60 protein calories
15 g total carbs - 7 g fiber - 4 g allulose = 4 g net carbs
4 g net carbs x 4 calories/g + 7 g fiber x 1 calorie/g = 16 + 7 = 23 carb calories
Total calories = 36 + 60 + 23 = 119 calories
This method wonāt give you exact numbers because some ingredients will have slightly different calories per gram, but we can get close enough to make sure that the label is accurate. Hopefully now you can understand where the calories in the Blue Unicorn bar come from and the only question remaining is āWhere did they get the magic from?ā
