Fitbit vs. online calc TDEE

MelAb8709
MelAb8709 Posts: 140 Member
in Health and Weight Loss
First I'll give my stats. 36 y/o female, 5'5", 185lbs, 38% BF.

I have a 9-5 deskjob. I wear a Fitbit and try to get close to 10k steps a day, most days land in the 7k range. I do bootcamp 2x a week, I try to go for a jog a couple times a week. I admit that lately, my exercise dedication has been mediocre and that's one of the things I need to work on.

So, my BMR is 1496. TDEE at sedentary is 1795, minus 20% = 1436. Is it a big deal to eat below BMR?

If I choose lightly active, TDEE is 2057, minus 20% = 1646.

Then there's Fitbit - Has anyone found these calorie expenditures accurate? According to Fitbit, my TDEE for the last week goes like this:

Wed 1919
Tues 1960
Mon 2331
Sun 1850
Sat 2061
Fri 2337
Thurs 2024

These numbers make it look like I'm not *that* sedentary as they're all above the TDEE of 1795 that I get from using online calcs. Unless Fitbit is inflating the numbers.

I haven't been losing weight, but then again I haven't really been trying. However, this needs to change because I am at a point now where I can hardly stand to look in the mirror. So I need to do it right or I will fail, again.

Thanks in advance, (and yes, I have read the sexypants, so you want a flat stomach, road map, etc., all extremely helpful.)

Replies

  • WalkingAlong
    WalkingAlong Posts: 4,926 Member
    The numbers look ok to me but did you do boot camps (and manually log them) on those two high days or something? Your average is around 2060 or 35% over BMR.

    Is it a Flex? Those are a little less accurate.

    You don't sound sedentary so I wouldn't expect sub-1800 values for you, from Fitbit. Though in my experience they over-credit activity and under-credit a sedentary day. I've seen my say I burned 6% over BMR on a sedentary day, which is ridiculous. But on the average, mine has been a good predictor for weight loss.

    You don't have to eat over BMR if you don't want to.
  • MelAb8709
    MelAb8709 Posts: 140 Member
    Yes - that Monday and Friday were both bootcamp days (which I do log manually, because I don't take very many steps during bootcamp) and that Thursday on the list I had gone for a run. When I log a run or bike ride using Runkeeper, Fitbit does double up on the activity and I end up having to delete it.

    I have a Fitbit One, and I agree with you - I used to have a Flex and my average steps did drop when I switched to the One. Not sure if that's because I don't wear the One 24/7, or because Flex is too generous, or a combo of both.

    I want to eat as many calories as possible (ha, doesn't everyone) - do you think it's okay for me to aim for Fitbit TDEE minus 300-400 calories/day?
  • StaciMarie1974
    StaciMarie1974 Posts: 4,138 Member
    MFP "Sedentary" means truly sedentary. Desk job and not much movement thru the rest of the day. Think couch potato. If you're averaging 7k minimum steps, I'd estimate that to be on the low end of lightly active - or perhaps just below lightly active but not really sedentary.

    I use a Fitbit and have found it to be reasonable on my burn #. Though I wear my One 24-7 unless charging. If you don't wear it all the time, it could be low depending on what you're doing when not wearing it.
  • WalkingAlong
    WalkingAlong Posts: 4,926 Member
    do you think it's okay for me to aim for Fitbit TDEE minus 300-400 calories/day?
    I lost a lot of weight that way (though going for 500-750 under). See how it works for you and adjust your deficit down, if needed. A lot of it depends on how well you log, I think. 300 can be missed in logging error for some.

    Good luck!
  • wiggleyum
    wiggleyum Posts: 8 Member
    According to Fitbit, my TDEE for the last week goes like this:

    Does the Fitbit really report TDEE each day? The calories are titled "Calories Burned", and I am wondering if you are interpreting it as TDEE.

    I could be wrong - I don't use the Fitbit website too much, so I'm not well-versed on its terminology. (I use the iPhone app and the display on the One itself and only occasionally go online.) But if it's really TDEE that is showing on the Fitbit, then I need to make some adjustments to my own calculations.
  • Francl27
    Francl27 Posts: 26,371 Member
    I'd trust fitbit more than TDEE calculators... but would use the average number and eat 20% less or something.
  • simplydelish2
    simplydelish2 Posts: 726 Member
    I found that the Fitbit is very unreliable as far as accuracy. I had the one and the flex - the flex is the most worthless piece of $100 equipment I've ever purchased. The one - a bit more accurate but not as user friendly. I wouldn't trust any of the Fitbit information.
  • cwolfman13
    cwolfman13 Posts: 41,865 Member
    First I'll give my stats. 36 y/o female, 5'5", 185lbs, 38% BF.

    I have a 9-5 deskjob. I wear a Fitbit and try to get close to 10k steps a day, most days land in the 7k range. I do bootcamp 2x a week, I try to go for a jog a couple times a week. I admit that lately, my exercise dedication has been mediocre and that's one of the things I need to work on.

    So, my BMR is 1496. TDEE at sedentary is 1795, minus 20% = 1436. Is it a big deal to eat below BMR?

    If I choose lightly active, TDEE is 2057, minus 20% = 1646.

    Then there's Fitbit - Has anyone found these calorie expenditures accurate? According to Fitbit, my TDEE for the last week goes like this:

    Wed 1919
    Tues 1960
    Mon 2331
    Sun 1850
    Sat 2061
    Fri 2337
    Thurs 2024

    These numbers make it look like I'm not *that* sedentary as they're all above the TDEE of 1795 that I get from using online calcs. Unless Fitbit is inflating the numbers.

    I haven't been losing weight, but then again I haven't really been trying. However, this needs to change because I am at a point now where I can hardly stand to look in the mirror. So I need to do it right or I will fail, again.

    Thanks in advance, (and yes, I have read the sexypants, so you want a flat stomach, road map, etc., all extremely helpful.)

    If you're walking 10,000 steps per day then you're not sedentary at all...add exercise to that, and I'm guessing your underestimating your activity level with the calculators and thus putting in faulty information...this is pretty common and in reality, most people are actually more active than they think they are even if they have a desk job.

    Ultimately though, everything is an estimation...you just have to go with it and make adjustments as per real world results. Nobody has a TDEE of exactly XXXX calories.
  • WalkingAlong
    WalkingAlong Posts: 4,926 Member
    According to Fitbit, my TDEE for the last week goes like this:

    Does the Fitbit really report TDEE each day? The calories are titled "Calories Burned", and I am wondering if you are interpreting it as TDEE.

    I could be wrong - I don't use the Fitbit website too much, so I'm not well-versed on its terminology. (I use the iPhone app and the display on the One itself and only occasionally go online.) But if it's really TDEE that is showing on the Fitbit, then I need to make some adjustments to my own calculations.
    Fitbit doesn't call it TDEE but that's what the calories burned is. Though you have to look at past days to get full day amounts.

    My favorite Fitbit display is now hidden. Click on View Profile and look at the first chart: 30 day graph of intake vs. burn. Look at the legend below it for your 30-day average burn. That's probably your best TDEE estimate, if you wear it and log workouts that it doesn't track. It also gives you your 30 day average intake (assuming you've logged 30 days). If those are 500 apart and you're not losing 4-5 lbs/month, something isn't getting tracked well.
  • ekat120
    ekat120 Posts: 407 Member
    I have the Flex and was unsure about how accurate the calorie count was when I first got it, too. People on here (some of whom have posted in this very thread!) told me it sounded like I was more active than I thought and that the estimates were probably pretty close to accurate.

    I've had it a little over 2 months now and have logged my food and weight at least 90% of those days. Based on my intake and weight during that time, I've found it to be pretty accurate for me.

    Like you, I try to hit at least 10k every day. I think I've missed on 2 days since I got it. So I can't really speak to its accuracy if you're very sedentary.
  • lemurcat12
    lemurcat12 Posts: 30,886 Member
    My favorite Fitbit display is now hidden. Click on View Profile and look at the first chart: 30 day graph of intake vs. burn. Look at the legend below it for your 30-day average burn. That's probably your best TDEE estimate, if you wear it and log workouts that it doesn't track. It also gives you your 30 day average intake (assuming you've logged 30 days). If those are 500 apart and you're not losing 4-5 lbs/month, something isn't getting tracked well.

    This is great.

    For the record, I've always found the Fitbit (even the Flex) pretty accurate for me. I just checked the 30 averages vs. my weight loss, and it is indeed right on the money.
  • mary659497
    mary659497 Posts: 484 Member
    Bump
  • MelAb8709
    MelAb8709 Posts: 140 Member

    Ultimately though, everything is an estimation...you just have to go with it and make adjustments as per real world results. Nobody has a TDEE of exactly XXXX calories.

    This is why I prefer to use Fitbit daily expenditure as the "TDEE" - because it's always different depending on how active or inactive I am that day. It seems like mine is probably pretty spot on - none of the calorie spends seem too high based on me not being that sedentary after all.

    I have Fitbit set to a 500 calorie deficit - I will give that a go for now and adjust if needed in a few weeks.
  • mary659497
    mary659497 Posts: 484 Member
    My 30 day profile states 2,137 avg burn, 1,637 average intake. I am 5 ft 1 inch. Would this be considered a healthy way to lose. I have been working on improving my health since beginning of May 2014.
  • MelAb8709
    MelAb8709 Posts: 140 Member


    My favorite Fitbit display is now hidden. Click on View Profile and look at the first chart: 30 day graph of intake vs. burn. Look at the legend below it for your 30-day average burn. That's probably your best TDEE estimate, if you wear it and log workouts that it doesn't track. It also gives you your 30 day average intake (assuming you've logged 30 days). If those are 500 apart and you're not losing 4-5 lbs/month, something isn't getting tracked well.

    Never noticed that before, thanks for pointing it out!
  • lemurcat12
    lemurcat12 Posts: 30,886 Member
    My 30 day profile states 2,137 avg burn, 1,637 average intake. I am 5 ft 1 inch. Would this be considered a healthy way to lose. I have been working on improving my health since beginning of May 2014.

    Sure, should be about a lb/week.
  • goldiebrawn
    goldiebrawn Posts: 4 Member
    You may want to check this out: http://****talens.com/the-most-difficult-client-in-the-world-short-overweight-women/

    Basically, he's saying that many TDEE calculators underestimate women's body fat percentages, which can throw off your TDEE calculations. Just based on data from his own clients, most women's body fat is best estimated in relation to their height - somewhere between 1.3 and 1.5 lb per inch. That would make your body fat percentage somewhere between 45% and 52% and would put your actual TDEE (by the Katch-McCardle equation) somewhere between 1240 and 1366. YMMV but I feel it's worth a read.

    It's also very possible that you're losing body fat but not necessarily weight. Are your clothes fitting better? Even with "extra" calories, with all the activity your are doing you are getting healthier and probably losing internal fat. Also for women our hormones can jack everything up and make it seem like we're not losing, when we are.
  • MelAb8709
    MelAb8709 Posts: 140 Member
    You may want to check this out: http://****talens.com/the-most-difficult-client-in-the-world-short-overweight-women/

    Basically, he's saying that many TDEE calculators underestimate women's body fat percentages, which can throw off your TDEE calculations. Just based on data from his own clients, most women's body fat is best estimated in relation to their height - somewhere between 1.3 and 1.5 lb per inch. That would make your body fat percentage somewhere between 45% and 52% and would put your actual TDEE (by the Katch-McCardle equation) somewhere between 1240 and 1366. YMMV but I feel it's worth a read.

    It's also very possible that you're losing body fat but not necessarily weight. Are your clothes fitting better? Even with "extra" calories, with all the activity your are doing you are getting healthier and probably losing internal fat. Also for women our hormones can jack everything up and make it seem like we're not losing, when we are.

    I had my bodyfat % measured with both of those little contraptions that you hold in your hands as well as via measurements by my trainer at the gym, I didn't use the TDEE calculater to figure it out.
  • Kalikel
    Kalikel Posts: 9,603 Member
    "Presley."

    Movie quote. 1000 calorie-free Thanksgivings to anyone who gets it. :)
  • ekat120
    ekat120 Posts: 407 Member
    Just based on data from his own clients, most women's body fat is best estimated in relation to their height - somewhere between 1.3 and 1.5 lb per inch.

    Interesting article (took me a minute to find thanks to MFP's censoring!), but this seems like such a vast overgeneralization.
  • zenhiker2014
    zenhiker2014 Posts: 84 Member
    My favorite Fitbit display is now hidden. Click on View Profile and look at the first chart: 30 day graph of intake vs. burn. Look at the legend below it for your 30-day average burn. That's probably your best TDEE estimate, if you wear it and log workouts that it doesn't track. It also gives you your 30 day average intake (assuming you've logged 30 days). If those are 500 apart and you're not losing 4-5 lbs/month, something isn't getting tracked well.

    This is great.

    For the record, I've always found the Fitbit (even the Flex) pretty accurate for me. I just checked the 30 averages vs. my weight loss, and it is indeed right on the money.

    It's been accurate for me too. I used it to hit my planned 500cal deficit/day, for a 1 lb per week weight loss, and did in fact lose an average of a pound a week for 20 weeks. That was using a Flex.

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