The Calorie Balance Equation – Part 2
by Erik Castiglione
Welcome to part 2 of the Calorie Balance Equation! In last week’s article, we discussed the equation, and how it’s actually more complicated than just Calories In vs. Calories Out. To refresh your memory, both terms in the equation are made up of multiple variables, as shown below:
Last week, we also discussed the pieces of Calories In. Now, we’re going to get into the Calories Out part. We have 4 components that comprise this part: Basal Metabolic Rate, the Thermic Effect of Food, Physical Activity, and Non-Exercise-Activity-Thermogenesis.
Let’s start with the simplest:
Physical Activity – this is any purposeful movement that you do during the day. This includes your CrossFit class, a walk around the block, a bike ride with the kids, yard work, etc. Frequently, this is what people try to increase in order to “burn off” the foods they eat. Unfortunately, this is very difficult to do, especially because it’s hard to estimate accurately how many calories you burn during activity. Unless you do your exercise in a hermetically sealed isolation chamber, you’re likely to be off by at least 10%. This is why we don’t subtract these calories from your daily total in our nutrition plans, but rather factor it in elsewhere.
Thermic Effect of Food – Have you ever heard the saying “you have to spend money to make money?” The same goes for food; in order to digest the food and absorb the nutrients, we must expend energy. THIS is where macronutrient balance and food quality really come into play. It takes more energy to digest less processed food. Additionally, you burn 20-30% of protein calories to digest it, 5-10% of carbohydrate calories to digest it, and 0-3% of fat calories to digest it. Hyper palatable, processed foods are high in both carbs and fat, making them easier to absorb. Typically, people who switch from a crap diet to a paleo diet lose weight because they end up eating more protein, fewer carbs, fewer fats, and less processed food. Considering that TEF accounts for 5-10% of your energy out, hopefully you can see how prioritizing food quality can help reduce caloric intake.
Non-exercise-activity-thermogenesis – NEAT refers to non-purposeful activity. This includes things like staying upright, fidgeting, and pacing while you talk on the phone. It varies greatly from person to person and day to day. It’s a small part of your caloric expenditure, but it still counts.
Basal Metabolic Rate: Your BMR accounts for roughly 60% of your calories out. This is based on weight, body composition, age, sex, genetics, etc. Generally speaking, men have higher BMRs than women, younger people have higher BMRs than older, bigger people have higher BMRs than smaller, and your BMR goes up with increased muscle mass. Hormones also come into play here – with hypothyroidism or hyperthyroidism, your BMR will decrease or increase, respectively. Regular exercise also helps to boost your BMR over time. Please note that CONSISTENCY is the key to this; there is no benefit to your BMR for doing excessive exercise. In fact, regularly overtraining causes your stress hormone, cortisol, to spike. This actually suppresses your metabolism.
So, now that we’ve covered the make-up of both Calories In and Calories Out, hopefully you can see that food quality, macros, exercise, and all other factors have their place. Calories may be the end all/be all, but they’re governed by everything else. Your body adapts over time, so you need to make sure to fuel it properly and consistently. If you starve yourself, your NEAT and BMR go down, as your body adapts. Your calories absorbed will also increase, because you need to get all the nutrients you can. Since you’re not eating, your TEF goes down. This is how your body stabilizes itself when you undereat. So, what’s the big takeaway here? Simple: eat quality food until you’re sated, not stuffed; exercise regularly and rest when you need to; and BE CONSISTENT. See you all in the gym…eventually.