Have you heard the expression, “A calorie is a calorie?” Some say that carbohydrate, fat and protein calories all effect body weight the same. This is total BS. They suggest that to lose 1 lb., you need to consume roughly 500 calories less each day, and that it doesn’t matter what type of calories you cut out or leave in as long as you cut your calories.
It might sound reasonable, but you guessed it, total BS! A calorie is not a calorie, in more than one way. Carbohydrate, fat and protein calories are each processed by the body in a distinct way, and each effect the body very differently.
1. The Thermic Effect of Food.
Thermic effect of food (TEF) is a fancy name for the energy needed to digest and absorb a meal. Our bodies use energy to chew, digest, absorb and metabolize what we eat; and the body uses different amounts of energy to process different nutrients. Generally, protein requires the most energy to process, then carbs, and then fat. Another way to say that would be to say that 2000 calories of protein adds fewer calories to the body than 2000 calories of carbs. While the differences aren’t gigantic, it’s worth mentioning as another example of how calories are not all equal.
2. If you cut your calories too low or for too long you will slow your metabolism.
To prevent starvation our bodies can metabolically adapt to conserve the limited number of calories we are eating. So, if you ever wondered why at one point you were able to lose weight by significantly reducing your calories but then suddenly it stopped working, this was likely what happened, at least in part.
3. Eating more protein and fat reduces appetite and increases satiety (meaning, you feel full).
Protein and fat are both highly satiating and require more time to empty out from the stomach leaving you feeling fuller, longer. Carbs have the opposite effect and make you crave more carbs. Additionally, consuming too many poor-quality carbs from sugars, refined grains, and processed foods trigger a series of damaging events leading to fat storage and the very real potential for a sick liver and heart, also known as Type II Diabetes and Heart Disease. This is not meant to scare you, but it should (huh?). Eating more protein throughout the day generally reduces your appetite more than if those same calories were instead consumed in carbohydrates. So, by increasing your daily protein intake without making a conscious attempt to eat less will likely result in eating less anyway due to reduced appetite. Just another example of how all calories are not created equal. It is important to note that all fats are not created equal either but, as a general rule, as long as you stick to natural fats from healthy sources you will be fine. More on that in Part 3 of this series.
4. Fiber helps slow the absorption of sugar and reduces overall calorie absorption.
Fiber is a form of carbohydrate that contributes to satiety without contributing calories, because it is not absorbed into the body. Just by consuming more fiber-rich foods without making a conscious attempt to eat less will likely result in eating less anyway due to reduced appetite, all while helping manage your blood sugar levels which results in more stable energy levels and less fat storage. So, a calorie from a high-fiber food is not equal to a calorie from a low-fiber food—yet a fourth way in which “a calorie is not a calorie.”
5. Timing of eating affects calorie processing.
Studies show that TEF is higher in the morning than in the evening. So, we burn more calories in the morning, another reason to make sure you’re eating breakfast! Also, worth noting, calories are more likely to be used immediately for energy or used to synthesize muscle proteins when they are consumed at times of energy deficit, such as first thing in the morning or after exercise. Many studies have shown that people build more muscle and gain less body fat (or burn more body fat) when they consume calories within an hour or two after exercise than when they do not, despite consuming the same total number of calories over the course of the day.
To be clear, counting calories has some value. However, for all the reasons above, you can’t count all calories equally in all circumstances.