Fitbit Walking Calorie Burn Estimate

Aaron_K123

Was curious as to the communities take of FitBit or activity tracker calorie burn estimates for walking.

In theory they have your height, your weight, an accurate step count and although I'm sure there is a range of burn associated with athleticism it seems like the estimate should at least be in the ballpark.

I also understand that my FitBit Charge HR adds my BMR so that if I lie in bed all day its still going to log that I burned 1800 calories that day.

With all that said my Fitbit seems to be suggesting that the amount of walking I do I should adjust something like 2000 additional calories per day (NOT including my BMR or baseline TDEE, that is additional).

To me that seems rather high and I am admittedly reluctant to eat 4000 calories as I can't help but feel this is a gross overestimate on its part. Rather than eat back 2000 I've been eating perhaps 400 or 500 extra a day for the walking. I am an avid walker/hiker and I can't help but feel like my body is a bit more efficient than that and that 2000 calorie burn is just wrong.

What are people's take/experience/thoughts on the accuracy of modern activity tracker calorie burn estimates?

taiannalynn

I'm trying to lose weight, so I generally stay far away from consuming the calories I supposedly burn. But I have noticed that if I am on my feet most of the day, rather than at my desk, even if I get approximately the same amount of steps, I am burning more calories. I have a Charge HR and I just assumed that it takes your heart rate in to account when it calculates calories burned.

Christine_72

I think my fitbit overestimates, even though i reduced my height and stride length by 3 inches. I recently upgraded from the zip to the Alta, so no HR monitor.

For comparisons sake, I'm 5'8, 148lbs, age 44. Yesterday i got an extra 850 calories synced over to MFP for 20,636 steps. According to Fitbit, my total burn was 2,607, and estimates my TDEE to be 2,451. If my fitbit was accurate i would have been at my goal weight eons ago.

I'm set to sedentary on here, I did have it at lightly active but i was losing at least a couple hundred calories every night, and hated being in the negative when i didn't get in enough steps for the day.

ETA: I "try" to eat no more than 50% of my calories back. The only exercise i do is walking.

Maxematics

We need more details, like what you did that day to earn 2000 extra calories.

I'm 5'3" and 108 pounds working on maintaining my weight. I use the Charge HR. Yesterday I earned 996 calories back via the MFP adjustment. I got in a bit over 25K steps, 9K of them being a 58 minute run in the park. The rest were from running errands throughout the day, constantly moving. It's important to note that my normal walking speed is approximately 4mph. My appetite has been low due to the weather, so I ended up leaving around 360 calories on the table, but I still ate 2067 calories. I've been eating between 1800 and 2400 calories per day for over a month and my weight trend still has me losing a bit of weight per week. Depending on what you're doing to earn those calories, and how much, it really doesn't seem that far-fetched. It's also important to note that I weigh all my food to the gram for the best precision possible. I only eat out once per week usually and it's at a health food restaurant that doesn't cook with salt, oil, etc., but I estimate a bit high when I do. Also, I don't do unlogged licks, bites, tastes either.

4legsRbetterthan2

My experience is all with a fitbit one which is steps only, so I am not sure how much the HR part of the charge will impact results.

I personally found my fitbit to be pretty darn accurate. I do not keep the accounts synced because I found that too annoying, which i will explain in the next paragraph. The reason that I think it is pretty accurate is that if I log as accurately as I can with MFP and use those numbers compared to the historical TDEE calculated by fitbit, my weight loss comes in really close to the deficit I created.

Make sure you look at the historical data and see that your fitbit calculated TDEE remained as high as originally projected. I know a couple years ago when I started using it fitbit had a tendency to assume you would continue at the same level of activity for the remainder of the day, which meant early morning workouts would sometimes cause inflated estimates early in the day. With it synced with MFP you would get large calorie adjustments that would then shrink if you returned to less strenuous activity. I am not sure if this ever got addressed or not.

I guess it is possible too that since I am using a one, and can only track steps, that mine does actually over-estimate but since non step based activity isn't accounted for it all evens out for me. Who knows?

Maxematics

4legsRbetterthan2 wrote: »

My experience is all with a fitbit one which is steps only, so I am not sure how much the HR part of the charge will impact results.

I personally found my fitbit to be pretty darn accurate. I do not keep the accounts synced because I found that too annoying, which i will explain in the next paragraph. The reason that I think it is pretty accurate is that if I log as accurately as I can with MFP and use those numbers compared to the historical TDEE calculated by fitbit, my weight loss comes in really close to the deficit I created.

Make sure you look at the historical data and see that your fitbit calculated TDEE remained as high as originally projected. I know a couple years ago when I started using it fitbit had a tendency to assume you would continue at the same level of activity for the remainder of the day, which meant early morning workouts would sometimes cause inflated estimates early in the day. With it synced with MFP you would get large calorie adjustments that would then shrink if you returned to less strenuous activity. I am not sure if this ever got addressed or not.

I guess it is possible too that since I am using a one, and can only track steps, that mine does actually over-estimate but since non step based activity isn't accounted for it all evens out for me. Who knows?

That's because your Fitbit food plan needs to be switched from "Personalized" to "Sedentary". You don't get the wild swing adjustments on MFP that way.

ForecasterJason

I think my Fitbit One overestimates my calories burned a bit. However, I have not set a stride length since I do believe my stride is different when I'm walking normally vs walking at a faster pace for exercise. What I discovered is that when I do exercise, it thinks my exercise intensity is higher than it actually is. In other words, I can walk at around 105 steps per minute on level ground, and it will think that is vigorous exercise instead of moderate intensity.

4legsRbetterthan2

Maxematics wrote: »

That's because your Fitbit food plan needs to be switched from "Personalized" to "Sedentary". You don't get the wild swing adjustments on MFP that way.

How do you do that?

Lourdesong

I gained 30 lbs over the course of 3 months eating my calories back from Fitbit.

A few things to note though, I was in my first trimester of pregnancy and had a ravenous appetite (no morning sickness), and it's more like I increased my activity to earn calories in order to compensate for my ravenous appetite than that I was active and just ate back what I earned. I would think it would work out the same regardless of my intentions though.

So yeah, I earned about 1000 calories a day (for 2800 total, 1000 above sedentary maintenance) and gained 30 lbs. I find it difficult to just blame the condition of (early) pregnancy for the gain, given that my maintenance should have been a little higher than it is when not pregnant.

I also was already of the opinion that Fitbit gets increasingly more inaccurate the more active I am. But I ignored that conclusion and pretended that wasn't so because I was hungry as hell.

BillMcKay1

IDk about the Fit Bit, but my Garmin VivoHR seems pretty accurate. At around 10,000 steps a day it brings me in at 2400ish TDEE, which fits pretty close with all the online TDEE calcs for sedentary (desk job) with light exercise at my height,weight and age. On lifting days it's around 2600-2700 TDEE

Maxematics

4legsRbetterthan2 wrote: »

Maxematics wrote: »

That's because your Fitbit food plan needs to be switched from "Personalized" to "Sedentary". You don't get the wild swing adjustments on MFP that way.

How do you do that?

Aaron_K123

Maxematics wrote: »

We need more details, like what you did that day to earn 2000 extra calories.

I'm 5'3" and 108 pounds working on maintaining my weight. I use the Charge HR. Yesterday I earned 996 calories back via the MFP adjustment. I got in a bit over 25K steps, 9K of them being a 58 minute run in the park. The rest were from running errands throughout the day, constantly moving. It's important to note that my normal walking speed is approximately 4mph. My appetite has been low due to the weather, so I ended up leaving around 360 calories on the table, but I still ate 2067 calories. I've been eating between 1800 and 2400 calories per day for over a month and my weight trend still has me losing a bit of weight per week. Depending on what you're doing to earn those calories, and how much, it really doesn't seem that far-fetched. It's also important to note that I weigh all my food to the gram for the best precision possible. I only eat out once per week usually and it's at a health food restaurant that doesn't cook with salt, oil, etc., but I estimate a bit high when I do. Also, I don't do unlogged licks, bites, tastes either.

Sorry if it wasn't clear from my post, I burned 2000 calories which was added to MFP when it synced by just walking, no running, no additional exercise. I usually get around 20k to 35k steps in so the 2000 calorie day was probably like a 30k step day. If that is accurate though my maintenance level is something like 4300 calories per day which seems extremely high, hence my skepticism. If I were to eat those calories back fully I'd have to be eating 3800 calories a day to lose a pound a week.

If you are curious about that specific day my diary is open, it was August 5th. Burned ~2000 according to fitbit which raised my allowance for 1 pound/wk loss from 1800 to ~3800. I ate an additional 700 calories that day but I didn't feel like eating the whole 2000 back was a good idea.

As for stride length it actually seems pretty accurate, if I walk from work to my house (6 miles) at the end I get ~12000 steps and it logs as 6 miles which by google maps anyways is quite accurate.

Aaron_K123

I'm of the opinon that in a perfect world of perfect TDEE calculations it is important to eat the calories back from exercise to maintain a steady weightloss and avoid extreme deficits that could result in uneccesary strain/stress and muscle loss.

That said given the world is not perfect and TDEE estimates can vary wildly I am skeptical of a 2000 calorie burn from just walking around. I've been eating probably a 1/2 to a 1/4 of my burn back as a result and just monitoring, I suppose after a few months I might have a sufficient snapshot in which to judge for my own situation.

karinabree

My experience in letting Fitbit calorie adjustment guide my intake is that I plateaued for a good month. When my sister in law enlightened me (you don't want to count calories burned walking to the bathroom!) I deleted the sync to fitness pal and logged my walking manually and started to loose weight again.

LivingtheLeanDream

I have found that Fitbit calculates my TDEE accurately, within 5% anyway.

WinoGelato

Aaron_K123 wrote: »

Maxematics wrote: »

We need more details, like what you did that day to earn 2000 extra calories.

I'm 5'3" and 108 pounds working on maintaining my weight. I use the Charge HR. Yesterday I earned 996 calories back via the MFP adjustment. I got in a bit over 25K steps, 9K of them being a 58 minute run in the park. The rest were from running errands throughout the day, constantly moving. It's important to note that my normal walking speed is approximately 4mph. My appetite has been low due to the weather, so I ended up leaving around 360 calories on the table, but I still ate 2067 calories. I've been eating between 1800 and 2400 calories per day for over a month and my weight trend still has me losing a bit of weight per week. Depending on what you're doing to earn those calories, and how much, it really doesn't seem that far-fetched. It's also important to note that I weigh all my food to the gram for the best precision possible. I only eat out once per week usually and it's at a health food restaurant that doesn't cook with salt, oil, etc., but I estimate a bit high when I do. Also, I don't do unlogged licks, bites, tastes either.

Sorry if it wasn't clear from my post, I burned 2000 calories which was added to MFP when it synced by just walking, no running, no additional exercise. I usually get around 20k to 35k steps in so the 2000 calorie day was probably like a 30k step day. If that is accurate though my maintenance level is something like 4300 calories per day which seems extremely high, hence my skepticism. If I were to eat those calories back fully I'd have to be eating 3800 calories a day to lose a pound a week.

If you are curious about that specific day my diary is open, it was August 5th. Burned ~2000 according to fitbit which raised my allowance for 1 pound/wk loss from 1800 to ~3800. I ate an additional 700 calories that day but I didn't feel like eating the whole 2000 back was a good idea.

As for stride length it actually seems pretty accurate, if I walk from work to my house (6 miles) at the end I get ~12000 steps and it logs as 6 miles which by google maps anyways is quite accurate.

Just to make sure I'm understanding, when you said you burned 2000, are you talking about total calorie burn on FitBit, a burn from a particular exercise, or the amount of the adjustment that MFP gave you after syncing with FitBit? I think it's the latter based on your other details but just want to make sure we are on the same page....

For what it's worth, I have always found FitBit to be fairly accurate and I've eaten back my calorie adjustments while losing, and now in maintenance. I used to have a Flex, and with average 14k steps/day and some light weight training it estimated my TDEE (total cals burned) to be 2200. I'm 5'2 and 120. I got a Charge HR a few weeks ago and so far haven't noticed any significant differences in what it estimates I burn or big changes in the amount of my exercise adjustment.

One change I made here on MFP when I first got mine and was having really big adjustments was to change my activity level from sedentary to lightly active (now active). I got good advice from veteran users that averaging 8-10k steps a day (at that time) wasn't really sedentary. When I did that, my baseline cals went up but the size of the daily exercise adjustments went down. I preferred having my adjustments more representative of my true exercise, not the steps I get as part of normal activity.

RoxieDawn

OP have you been on the fitbit community forums regarding your issue? There are tons of things out there with others having the same problem.

I do not know the details of you issue, so it is hard to tell you anything without physically looking at your data, etc.
Others in the fitbit community made some adjustments (in Fitbit, not MFP) and also noted how fit bit is handling the heart rate, walking strides, calibration of the unit, margin of error, etc..

As I do not want to make assumptions, so do searching on the Fitbit forums, because I saw a lot in there about this when I researched this for myself from within my account.

bshrom

In my opinion there is no way that the calorie burn listed on our fitness trackers accurate. Some days my calorie burn on mine says like 2500 calories, well if I was burning that much just from walking I should be losing a whole heck of a lot more weight than I am. So I vote for not accurate at all.

Gallowmere1984

You mentioned hiking. What kind of duration and vigor are we talking here, on the days you see those high burns? Everything I have plugged into, for a six hour hike (not unreasonable in my experience) is showing around 2500 kcals burned for that, even at my height and weight of 5'10", 152 lbs.

Christine_72

bshrom wrote: »

In my opinion there is no way that the calorie burn listed on our fitness trackers accurate. Some days my calorie burn on mine says like 2500 calories, well if I was burning that much just from walking I should be losing a whole heck of a lot more weight than I am. So I vote for not accurate at all.

Yep same, same. Eating back half seems to be working for me.

The one caveat i would add, is if you are going to eat back any exercise calories then you'd want to be sure your food logging is as accurate as possible. Underestimating calories in and overestimating calories out most always equals no or minimal weight loss.