Most people start counting calories when they are trying to lose weight. For my clients, I usually have them track food for a few days to get an idea of what they are currently eating. But calorie counting isn’t something I normally recommend to my clients. There are a number of reasons why I don’t think calorie counting is the best method for long term weight loss or health, but that’s not what today’s post is about!
Before we talk about counting calories, I should probably quickly define a calorie for you, just so we are all talking the same language.
Calories or kcals, represent the amount of heat required to raise the temperature of one kilogram of water by 1 degree centigrade. Thus calories represent the potential energy stored in food. Heat is used to measure the potential energy in food (remember we are raising one kilogram of water by 1 degree to calculate out a Calorie). When you read calorie in this post, I am referring to a Calorie or kcal. Ok, now that we have that all cleared up, lets talk about calorie myths and facts!
Here are a few things you might not know about counting calories.
1. Did you know that scientists measure the calories in your food by combusting the food with a device called a bomb calorimeter. Electrical energy is used to ignite the food, and as the food burns, it heats up the surrounding air. The air expands and escapes through a tube that leads the air out of the calorimeter through a copper tube. As the air escapes through the tube, it heats up the water around the tube. To calculate the calories in the food, you simply record the change in the temperature of the water. Pretty cool huh? Sound like exactly what happens in your body right?… Well no, not exactly.
Using the bomb calorimeter here are the average calories per gram of macronutrient:
- 1 gram fat = 9.44 Calories
- 1 gram of starch = 4.18 Calories
- 1 gram of sucrose = 3.94 Calories
- 1 gram of glucose = 3.94 Calories
- 1 gram of protein = 5.65 Calories
- 1 gram of alcohol = 7.09 Calories
Did you notice something off about the list above? If you are a hard core macronutrient counter, I know you did! You probably said, I thought 1 gram of protein had 4 calories, not 5.65! What’s going on? Well you are right, this is because our bodies are not bomb calorimeters. And it takes ENERGY (or calories) to break down food. And protein takes the most energy to digest. By the time you are done digesting protein, you are only left with 4 calories worth of energy.
So Fact One: Your body needs energy to digest food, and our bodies are able to use about 91% of the energy present in our food for energy transfer in the body!
Fun Fact Two: When consuming resistant starches/fiber, our bodies don’t get as much energy from these foods as what is shown when those foods are burned in the bomb calorimetor. So when you are looking at the calories in resistant starches (hello beans, legumes, oatmeal, and even cold potatoes), the calorie numbers on the package are often overestimated! This is because your body doesn’t digest resistant starches and thus you can’t access all the calories from these foods.
Fun Fact Three: The nutrition information used by manufacturers to estimate the calories in your food may be based on outdated information from a nutrient database. Yup, this means that all those numbers you obsess over on myfitnesspal are likely overestimated/underestimated as well.
Fun Fact Four: When manufacturers make a new product, they do all the math to estimate the calories per serving. But often these ingredients can change slightly batch to batch, so the number on the package may not represent what you are actually eating!
Fun Fact Five: Did you know that the diet of the animal you are eating can change the calorie and micronutrient profile (vitamins, minerals, phytochemicals)? Same goes for the plants you are eating. How ripe a fruit or vegetable was at harvest can change the calories and micronutients. Another factor in the micronturients of your food, the quality of the soil. If your food was grown in very poor soil, it’s likely not full of all those beneficial micronutirents. Oh, and if your food had to travel long distances or sit in cold storage for months, it’s probably less nutrient dense than it was when it was harvested.
So what does all of this mean. Well here is the kicker. The energy (calories) and nutrients on the food labels or nutrient databases have an error of margin of +/- 25%
Seriously 25%. And here you are obsessing because you went over 12 calories or over on carbs today.
This is why I can’t ask my clients to spend their days counting calories and often recommend them not to count them. They are an impractical measurement of what you are actually giving your body. I say if you want to count something, count the number of vegetables and fruit you are eating, and how many glasses of water you are drinking everyday. This is a core practice in my Back to Basics Nutrition Course where I show you how to do this.
You should try to eat mostly foods that went from farm to table with minimal processing in the middle. The more “stuff” companies do to your food, the more you should pay attention to the “calories” in it.
I hope this shed some light on counting calories. Although it’s a great way to become aware of the food you are putting in your body, it’s not something you should be obsessing over.
Want more info on calorie and macro counting? Check out the below video.
What about you?
- Any fun facts about calories you want to share?
- Do you get annoyed when the same food can have two or three calories in an app like MFP or LoseIt?
- Do you normally count calories?