Calorie burn estimate by Ionic % of error?

[Blake]

I am in the process of really nerding out with my diet.  I understand you don't want to run a huge deficit whilst trying to lose weight.  I think the highest calorie deficit recommended is something like 20%?  I could be wrong.

Either-way, on the average I am consuming 2000/2100 calories a day and burning about 3300 cal a day according to my Ionic.  This is creating a calorie deficit of about 37%, I suspect a bit on the high side.

I am eating Keto, and I do light cardio daily and lift heavy 2-3 times a week.  Other than that I sit, for work, and at home.

Most calculators online I used recommended I consume at the most 2000\2100 calories for weight loss with my measurements and activity level.

Anyway, I am just trying to get an idea of how accurate the calorie burn of the Ionic and or Fitbit is in general.  Your help and input is greatly appreciated.

[Rich_Laue · Accepted solution]

The accuracy of the calorie content would depend on how accurate you entered your stats, height, weight, gender, etc.

Every with that, Fitbit assumed that the user is an average person, since their is only one average person, this will also add a little error.

So how accurate is it? Don't know

[Blake]

Didn’t mean to mark that as the solution but oh well.  I did forget to mention that I update my weight daily. So Fitbit knows my height weight age etc. I even try to select activities when I do them for logging purposes. Nonetheless there has to be a degree of error / give or take with logging calorie burn. Curious if Fitbit has made that value known. 

[Rich_Laue]

Well @Blake if you tap/click on the 3 dots to the right of the post, you will see an entry that says "Not a Solution", this is used to unmark a post as a solution. There also is an entry when the post is yours to edit your post.

As for the error % I think this would vary from person to person, since very few will be exactly like the average male and female. Also as a person gets more fit, there heart becomes, more efficient, requiring less calories to pump the same amount of blood. I'm not sure how the rest of the body works with efficiency. For an out of shape person, they may get easily tired during a walk while a for person with more muscle but at the same weight will easily go the course even though they both have elevated heart rates. Do they both burn the same calories? It would be moving the same amount of weight, over the same distance, but the out of shape person will take a longer time.

I wonder if Garmin or Apple publish their caloric error. I also no that measuring the O2 consumed using a mouth piece is a lot more accurate than using the changes in heart rate with the amount of O2 in the blood. Then again the mouth piece is not as accurate as measring the rate of Oxygen decreasing in a room while the participant exercises in in the sealed room, but have never seen a percentage for tye different methods of measuring caloric burn.

I still question this whole caloric burn measurement, do we as humans burn the calories in food with the same efficiency as the calories needed to burn the same amount of food in a petri dish?

We measure our caloric burn based on how many calories are needed to burn an item outside of the body.  

Example: it requires 25 calories to burn 61 grams of carrots that are on a petri dish in the lab, therefore we say the carrot contains 25 calories. We know how much Oxygen has been consumed during this process to burn the carrot, therefore we assume that if the body burns the same amount of Oxygen then the body has also burnt 25 calories. Nowhere have I seen any testing to prove that this theory is correct. Does every body get the same amount of calories out of the same food? Thoughts to ponder.

[Blake]

Thanks Rich, this makes sense.  You would think there is still some generic margin of error. 

[Kylnk92]

I'm sure there is, but I'm struggling to find that margin of error, too. Unfortunately, the research I've seen so far compares different smart watch brands, not specifically the Ionic.