I frequently preach the importance of understanding the “calories in vs. calories out” for losing body fat or gaining muscle mass. It’s an important concept to understand because it determines whether you lose, maintain, or gain body weight. It is also valuable to understand that not all calories are 100% equal, and not all calories are as they appear.
The Thermic Effect of Food
The thermic effect is the calorie burn that happens during digestion. Approximately 25% of calories from protein are burned off during digestion, 6-8% from carbohydrates, and 2-3% from fat, as cited in The Lean Muscle Diet by Lou Schuler and Alan Aragon (and numerous other sources). This means that one quarter of the calories you eat from protein are actually burned off before you even exercise.
According to nutrition coaching program Precision Nutrition, the thermic effect of food contributes to about 10% of the total calories you burn for the day. This is not an overwhelming portion, but it’s enough to affect change. Check out Burn More Calories While You Eat to learn more on how to use this principle as a fat loss tool.
The Calories You Eat Affect The Calories You Burn
Calories are units of measurement for energy. Therefore, the calories you eat (energy you are taking in) affects how many calories you can burn (the energy you are putting out). This is important to understand when trying to lose body fat.
While it’s easy to think all you have to do to lose weight is eat less, this isn’t so simple. If you eat too few calories, you’ll have so little energy that you won’t burn enough calories to lose weight. This makes the calories in vs. calories out formula more complex than a simple math equation.
Food Label Inaccuracies
Food labels give us a great guide for knowing our calorie intake; but alas, no system is perfect. The FDA allows companies a 20% margin of error for their nutrition labels. This means your 100 calorie mini-cookie bag might have closer to 120 calories.
If you are using the nutrition information provided by restaurants to count your calories, understand this information should also be viewed as helpful guide rather than cold-hard fact. If a dish at a restaurant lists 600 calories, who’s to stop the chef from adding an extra serving or two of oil (e.i. extra calories) to your dish to enhance the flavor?
What This Means For You
All these nuances make the calorie more complex than you might have realized. It doesn’t change the fact that you must reduce calories to lose body fat, but it should influence how you shape your nutrition. To mitigate these factors, your diet should include plenty of protein, lots of nutrient-rich foods, and most of what you eat should come from whole food sources rather than packaged or processed ones.
So while this information about calories might be new to you, the recommendations for healthy nutrition are still what you’ve been taught your whole life.