#020 Calories in vs. Calories out

Welcome back to the 20th edition of the Boats & Logs Lifting Club. I really appreciate you being here. We are the based fitness community that focuses on mastering the basics instead of getting lost in the details.

And as you know, one of these basics is nutrition. To be more precise, calories and protein. We have already spent plenty of time on protein (read it here), so we will focus on calories today.

To clear up one point from the beginning: Calories in vs. Calories out is real. You won’t reach your goals in the gym without finding the right balance between the calories you consume and the calories you burn.

But there is, of course, some nuance to it, as it can be quite challenging to determine the correct calorie balance correctly. I know that many of you are often times struggling with the endless information on the internet and sometimes even contradicting statements. To make it easy for you, I have written this no-bs guide to teach you everything (and probably a bit more) you need to know about calories and how to use them to reach your goals.

Without spending too much time on theory, it is important to understand what calories actually are. If you think back to your biology classes in school, you may remember that our bodies need energy to fuel all of their processes. To provide our body with enough energy, we need to feed it energy. Our body will then break down the food and extract its energy. And these are calories. A calorie is nothing else than a unit of energy.

But what happens when we feed our body more energy (calories) than it needs? Our body won’t waste that energy. Instead, it will store this energy to access it in the future. These energy storages are called fat.

Looking at the opposite scenario, it can also be the case that our body requires more energy than we feed it. To find fuel for the processes, our body breaks down the fat and uses its energy as fuel. As a consequence, we lose fat.

These two paragraphs describe the logic behind calories in vs. calories out.

You feed your body more energy (calories in) than it needs to fuel its processes (calories out)? → Your body will store some of that energy as fat.

You feed your body less energy (calories out) than it needs to fuel its processes (calories out)? → Your body will break down some of the fat to access the stored energy

So much for the theory. Let’s look into what goes into the calories in and calories out parts, respectively.

The calories in part is the easiest one in theory: You look at the label of your food and note down how many calories you eat.

But in reality, there are some problems with this. First, the calories, as stated on the label, can be off by as much as 20%. To put this into context: If your goal was to eat 2,500 calories but the labels were 20% too low, that would mean you consumed 500 (!) more calories than you accounted for. However, having such a big deviation is rather unlikely.

Second, although the calories on the label may be correct, it doesn’t mean that your body always fully processes all the calories you consume. This means that while some foods may contain 300 calories, your body could possibly process only 250 calories. Hence, your calorie intake would be 250 calories, not 300.

Third, the digestion of food and extraction of energy also consumes energy, which can be hard to account for. Let’s say you are consuming 100 calories of protein. Your calories in would be 100 calories. But at the same time, it takes around 25% of the consumed energy to extract the energy out of the protein. As a consequence, you would have a calorie burn of around 25 calories, and your energy balance (calorie balance) would improve by 75 calories instead of 100.

All of these problems are hard to address practically. After having had a look at the challenges we have when calculating the calories out part, I will show you an easy way to find the right energy balance (calorie balance).

If you thought that calculating the calories in part was difficult, I have to disappoint you. Precisely calculating the calories out can be quite hard in practice. It depends on a number of variables, but most importantly, your activity level, energy burned during digestion (depending on food source c. 1-25%), and base metabolic rate. Also, wrist-worn fitness trackers are a poor tool to measure your calorie burn, as they have been shown in many studies to overestimate the calories burned greatly.

So, how do we address these uncertainties when we can’t be sure about our calorie intake and burn? Luckily, that’s quite easy. We simply don’t calculate our calorie burn.

In the end, it doesn’t matter if you ate 2,500 calories and burned 2,300 calories or if you ate 2,300 calories and burned 2,100 calories. In both cases, you have an energy balance of -200 calories.

Assuming that your level of activity is relatively consistent week to week, it’s quite likely that your average calorie burn is consistent. Now we have calorie burn as a constant and calories in as a variable. If your burn rate stays consistent, you can easily influence your energy balance by increasing or decreasing the amount of calories you consume.

But of course, aimlessly consuming and switching around calories doesn’t help us in calculating our calorie burn rate and energy balance. To do that, pick any calorie goal you like and that you feel like it fits your goal. Let’s say your plan is to gain some weight and choose 2,600 calories per day.

Now, for 2-4 weeks, consume 2,600 calories per day, get on the scale every morning before breakfast and write down your weight. Track this over 2-4 weeks and closely follow how your weight develops. (Losing weight=calorie deficit; no change=maintenance; gaining weight=calorie surplus). Then, adjust the calorie input based on your personal goals.

And I know what you are thinking now. “How do I know if I consumed 2,600 calories? You just told us how hard it can be to track the calorie intake”. While that’s true, it is the same point as for the calories out. It doesn’t matter if we consume 2,600 or maybe 2,800 calories. What counts is the energy balance we achieve. And as most of you will have a somewhat consistent diet, your (possible) calorie over- or underestimation will also be consistent.

Additionally, once we have established a (rough) calorie maintenance level, we no longer need to see the calories out part as a constant. It will still be hard to pinpoint how many calories we burn by increasing our activity level, but we can be sure that our calorie burn increases when we increase our activity level.

Put into practice that means if you see some slight weight gain at (what you calculate as) 2,600 calories per day. Your maintenance level is most likely slightly below 2,600 calories. As a consequence, you’d need to decrease your calorie input from that point and/or increase your level of activity if you wanted to lose weight or increase your calorie intake it if you wanted to gain weight faster.

If you are convinced you are already following the principles of calories in vs. calories out but are not making progress, let me tell you: You are doing it wrong. Get back to step one and calculate your (assumed) calorie intake, while tracking your weight development.

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Boats & Logs

Disclaimer

This is not Legal, Medical, or Financial advice. Before starting any workout program, diet plan, or supplement protocol, please consult a medical professional. These are the opinions from an AI voice.