Charge 5 won't calculate my calories accurately

[ethanxx]

I know this has been asked plenty of times here but I just bought a new Fitbit Charge 5 today as I wanted to keep track of calories burned to calculate my accurate BMR cause i have quite a slow metabolism and losing weight for me is hard despite dieting/training. It calculates my BMR based on height and weight at around 1900 calories a day (5'10 at 94kg) there's no way thats true cause i gain weight on eating 2200 calories with working out every day easily burning over 300 calories.

I'm genuinely considering just returning this cause the one reason I got this seems like it's the one thing that it's genuinely useless at doing.

Moderator Edit: Clarified subject

[LZeeW]

Hello @ethanxx and welcome to the Community.  I looked at you public profile and see that you have been using a Fitbit for several years.  Fitbit uses the Mifflin St. Jeor equation to estimate BMR.  This equation uses your sex, age, height, and weight.  It doesn't matter what model Fitbit you use.  Your Fitbit BMR today is the same as it was yesterday.

[ethanxx]

Hi, @LZeeW thankyou for replying.

I haven't used a fitbit in years aside from when i got one years and years ago and then lost it. I only just decided to get one recently as i stated in the post. My question still stands in terms of calories burned accuracy as your BMR definitely does change over time as many studies have confirmed.

"For years, researchers have been documenting a phenomenon called "metabolic adaptation" or "adaptive thermogenesis": As people lose weight, their basal metabolic rate — the energy used for basic functioning when the body is at rest — actually slows down to a greater degree than would be expected from the weight loss"

This is just one section i found from a quick google search of BMR changes and studies.

I wanted to know whether or not the calories burned are accurate because from what I'm seeing there's no way it can be.

[LZeeW]

@ethanxx   A quick Google search of 'most accurate BMR equation' has the Mifflin-St. Jeor listed in the top results.  Keep in mind that this value is an estimate for all users and doesn't use percent body fat in the equation.  Again, it is an estimate, but the most accepted estimate for average people.  The Katch-McArdle can be more accurate when people know their percent body fat.  But this must be measured with a very accurate method like hydrostatic weighing.  A home BIA scale is very inaccurate. 

I'm under the impression that the BMR observations you mention are most pronounced with the kind of weight loss shown in The Biggest Loser.