Comment by nathanaldensr

In my experience TDEE calculators are mostly best guesses and the more expensive the bestester the guess. This is mostly showing in various age ranges and pregnancy, you can expect variance compared to what is calculated. (not sure which method was used for this study as the calculated baseline for what was their expected TDEE) The use for this with TDEE is expect variance in age ranges in the graphic, ultimately there is no way to know until you test yourself with a diet for a few weeks.

The biggest thing is showing how much mental stress plays into calorie burning, enough where an average western lifestyle can have the same calorie burned as a hunter gatherer.