And whatever the method you use to track your TDEE, the results can be enlightening.

I certainly thought so.

What is TDEE?

Before I get into what I learned, heres a quick refresher on TDEE.

As the name states, it is an accounting of yourtotaldaily energy expenditure, or calorie burn.

People will often estimate their TDEE using a formulalike this one, from tdeecalculator.net.

That would be 2,200 for the day.

Butexercise doesnt burn as many calories as youd think, so your numbers will likely be off.

Why does your TDEE matter?

If you eat more than your TDEE, youll gain weight.

If you eat less than your TDEE, youll lose weight.

Thats the whole idea behind the concept of acalorie deficitor surplus.

(If you eat the same amount as your TDEE, your weight should stay the same.)

There are plenty of caveats to this process, but its the model were working with.

So Ill have some enchiladas, and log them in the app (480 calories).

Later Ill have a banana (105 calories), and so on.

By the end of the day, Ill have a total for how many calories I ate.

Meanwhile, Im also weighing myself every day, or at least most days.

The app or the spreadsheet simply relates the two.

That means if Im eating 2,000 calories on average, my TDEE must be 2,500.

If my weight is staying steady, then the amount Im eating must be equal to my TDEE.

But it doesnt really work that way.

Our food labels cant precisely reflect all of that.

Similarly, the number of calories we get from a given food is also a rough estimate.

Theyre not all going to beexactly105 calories.

There are likewise plenty of uncertainties when it comes to calorie burn.

If you have a salty meal, your weight will be up the next morning.

If you drink a few beers, you may be a bit dehydrated and see the scale go down.

This could change your calculated TDEE, but it doesnt change how many calories your body is actually burning.

Or, as the scientists like to put it:All models are wrong.

Some models are useful.

And this one has been pretty useful for me.

It thinks I probably burn 2,090 calories per day.

Even given the caveats above, this information is helpful.

Yes, but not always in the direction my TDEE would indicate.

Lately Ive just been doing the heavy workouts and going for a daily morning walk.

This is also why it doesnt make sense to track the calories you burn in each workout.

I dont track most of my workouts, so sadly I cant go back and compare the estimates.

The most noticeable difference is simply how much Im eating.

It might seem counterintuitive, but the more I eat, the higher my burn goes.

But thats not the only possible explanation.

Ive always preferred to think of maintenance as arange.

For me that might be something like 2,350 to 2,550 calories.

Now, my maintenance burn is 2,500.

If I want to lose weight, I only need to go down to about 2,100 calories per day.

To gain, I need to eat close to 3,000.

Briefly, the bigger you are, and the more non-fat tissue you have, the higher your metabolism.

Age, surprisingly, doesnt factor into it much at all once you account for those two factors.

Im not sayingallof the difference is muscle, but probably a lot of it is.

And since I wasnt as strong, I was handling lighter weights.