By Adam Bisek
Many people set out on their own dietary excursion with the best of intentions to build muscle or shed body fat. However, even the best of intentions can be haphazard. Unless you’re initially calculating your estimated metabolism (caloric expenditure), tracking your diet closely, and then making appropriate adjustments thereafter, you're practicing the dietary equivalent of throwing doodoo at the wall and seeing what sticks. While the mathematics of calories in versus calories out are essentially a well-educated approximation, it’s still a significantly better approach than arbitrarily switching your breakfast to bacon and a half-stick-o-butter coffee because your co-worker Karen lost 10lbs on keto. The reality is that if you’re not measuring your dietary practices, you’re not truly attempting to manage your physical change or your health.
Understanding the “Metabolic Equation”
In order to put the proper steps in action you need to understand what goes into calculating your “metabolism,” which, in this context, is how many calories you burn within a day. Always remember that we use pretty finite numbers when we calculate and assess caloric intake and expenditure, but these numbers are in actuality only a good approximation of a moving target. Several components make up the total amount of calories you burn in a day, or what is called your Total Daily Energy Expenditure (TDEE), they are as follows:
Basal Metabolic Rate (BMR): This is essentially the amount of energy (calories) you expend doing absolutely nothing, essentially what you would burn laying in bed all day and not moving. This makes up ~60-70% of your TDEE and can be a bit variable based on things such as one’s muscle mass. As you can see this makes up the majority of the calories you expend within a day.
Thermic Effect of Food (TEF): You actually burn calories simply by processing the food you eat. This can be up to ~5-10% of your TDEE, the variance here could be attributed to metabolic adaptation, something will casually breeze by in a moment.
Non-Exercise Activity Thermogenesis (NEAT): This is just a long-winded way of saying the movement you do during the day that is not structured exercise, basically the movement you’re not conscious of. This number is relatively sensitive to chronic caloric balance, that is to say if you have been dieting for a while one’s non-conscious activity tends to decline. This is where using daily step count helps to assess someone’s level of NEAT, however, this is more a proxy of NEAT. The reason I say it that way is that if you start counting your steps and shoot for a step goal, this becomes structured physical activity.
Exercise Activity Thermogenesis (EAT): This one is simple, it’s the measure of energy expenditure you have through structured exercise. This number is governed by the duration and intensity of the exercise. Although I will show you a different way of calculating activity in this article combining NEAT and EAT, another simple way to calculate EAT on its own is to use Metabolic Equivalents (METs) of exercise. This number depicts the intensity of particular exercises, you then throw in your body weight and duration of exercise into an equation and your calculator will spit a good estimate of how many calories you're burned during your training session. To be honest this method is probably just as good if not better than today’s wearable fitness technology.
*Metabolic Adaptation: You see the asterisk here because “metabolic adaptation” isn’t really a component of the TDEE equation, but rather a phenomenon that affects it. Essentially your body, your metabolism will adapt to changes in your consistent energy (food) intake, energy expenditure, and weight change. When you see someone’s weight loss stall when they’re diet and exercise regimen is the same this phenomenon is most likely happening. The exact physiological nuances as to how and why this happens are a bit out of the scope of this article. I simply want you to appreciate that this process happens over time whether in a consistent caloric surplus or deficit; your metabolism adapts to the conditions at hand and can toggle towards meeting one’s energy balance over time.
Figure 1. TDEE visual depiction (strongbody.coach.com)
In the next article we will talk about how to calculate your maintenance calories using the numbers associated with each of these.
Figure 1. TDEE graphic (https://stongbody.coach/you-can’t-out-train-bad-diet-part-2-eating-exercising-fat-loss/)