Fitbit TDEE seems low?

LaurenAOK
LaurenAOK Posts: 2,475 Member
in Health and Weight Loss
I got a fitbit for Christmas but just decided to start using it yesterday. The TDEE it estimated for me at the end of the day seemed really low and I wanted to get some opinons. It said that even after burning about 400 calories through exercise, my TDEE for the day was only about 2000 calories. That means without exercise, my TDEE would only be 1600 calories a day.

This just seems low to me. MFP estimates my TDEE without exercise to be 1800 a day, which sounds a lot more accurate to me? This is the number I've been going off of for a year and losing weight. I'm 5'4", 130 pounds. I don't have a job right now so I'm not super busy but I complete basic daily tasks such as cleaning the house, cooking, going grocery shopping, etc. Does anyone know if the fitbit tends to estimate low, or have I been estimating my TDEE too high this whole time? Sometimes I haven't been losing weight as quickly as I want so maybe I've been eating too much. But idk, other times I have lost weight right on track or faster than expected. I'm just confused.

Replies

  • honeysprinkles
    honeysprinkles Posts: 1,757 Member
    I have looked into getting a fitbit before, but I'm just not sold on their accuracy, I don't see how it can really measure it correctly. I just stick to my heart rate monitor and myfitnesspals estimates.

    A good way to check (but would be a little annoying probably) would be to eat the amount it estimates for you for a few weeks and see if you lose or maintain!
  • honeysprinkles
    honeysprinkles Posts: 1,757 Member
    I don't have a job either right now, so I set my activity level to lightly active and the maintenance amount that I got was 1740 calories a day...however, I think that might be low because I'm losing more than what my weekly deficits estimate that I should most weeks! So 1600 does seem a little low. But I'm also taking oxyelite pro right now, and I have no idea if that contributes but I thought I'd mention it in case it does!
  • LaurenAOK
    LaurenAOK Posts: 2,475 Member
    I don't have a job either right now, so I set my activity level to lightly active and the maintenance amount that I got was 1740 calories a day...however, I think that might be low because I'm losing more than what my weekly deficits estimate that I should most weeks! So 1600 does seem a little low. But I'm also taking oxyelite pro right now, and I have no idea if that contributes but I thought I'd mention it in case it does!

    Thanks! Yeah I'm set to "lightly active" as well, because I don't believe anyone is truly "sedentary" unless they're literally sitting in bed all day every day. It seems low to me too. I see women on here my size who eat 2300 calories a day and lose weight!
  • LaurenAOK
    LaurenAOK Posts: 2,475 Member
    I have looked into getting a fitbit before, but I'm just not sold on their accuracy, I don't see how it can really measure it correctly. I just stick to my heart rate monitor and myfitnesspals estimates.

    Forgot to mention, the fitbit is very enjoyable! I'd recommend it even if it is a little off :)
  • shadow2soul
    shadow2soul Posts: 7,692 Member
    It could be possibly on the low side. I haven't had mine long(April 26), but here is what has happened for me:

    Total Burn (since I started using it): 35206
    Total Eaten (Since I started using it): 27362
    So deficit ends up being : 7844 / Loss of 2.24lbs
    Total Loss (since I started using it): 4.9lbs
  • honeysprinkles
    honeysprinkles Posts: 1,757 Member
    I don't have a job either right now, so I set my activity level to lightly active and the maintenance amount that I got was 1740 calories a day...however, I think that might be low because I'm losing more than what my weekly deficits estimate that I should most weeks! So 1600 does seem a little low. But I'm also taking oxyelite pro right now, and I have no idea if that contributes but I thought I'd mention it in case it does!

    Thanks! Yeah I'm set to "lightly active" as well, because I don't believe anyone is truly "sedentary" unless they're literally sitting in bed all day every day. It seems low to me too. I see women on here my size who eat 2300 calories a day and lose weight!
    I wasn't even paying attention to what I wrote, I actually have mine set to sedentary! so 1600 definitely seems low! I used to have mine to lightly active but I changed it and now I just add in extra activity!
  • Cobwellac
    Cobwellac Posts: 75 Member
    I would trust the Fitbit over some calculator that just gives estimates. Keep in mind that the Fitbit can be off by 10% up or down. You said you've lost weight more slowly than expected using the calculated TDEE; I think that says it all. My TDEE is estimated on the calculators at 1800, but I KNOW I burn a lot less. I make it up there only after pretty vigorous exercising.
  • lcfairbairn74
    lcfairbairn74 Posts: 412 Member
    Are you adding in your exercise separately? Fitbit isn't good at tracking some forms of exercise and underestimates the calorie burn.
  • tahinilove
    tahinilove Posts: 72 Member
    This is interesting. I find that my fitbit gets so high for me! I think it levels out though as it doesn't pick up weight lifting burn!
  • luckydays27
    luckydays27 Posts: 552 Member
    I got a fitbit for Christmas but just decided to start using it yesterday. The TDEE it estimated for me at the end of the day seemed really low and I wanted to get some opinons. It said that even after burning about 400 calories through exercise, my TDEE for the day was only about 2000 calories. That means without exercise, my TDEE would only be 1600 calories a day.

    This just seems low to me. MFP estimates my TDEE without exercise to be 1800 a day, which sounds a lot more accurate to me? This is the number I've been going off of for a year and losing weight. I'm 5'4", 130 pounds. I don't have a job right now so I'm not super busy but I complete basic daily tasks such as cleaning the house, cooking, going grocery shopping, etc. Does anyone know if the fitbit tends to estimate low, or have I been estimating my TDEE too high this whole time? Sometimes I haven't been losing weight as quickly as I want so maybe I've been eating too much. But idk, other times I have lost weight right on track or faster than expected. I'm just confused.

    From my experience, fitbit gives you the net calories burned from exercise when you enter it. If you burned 400 cals from exercise, a portion of that is cals that you would have burned if you sat on the sofa. For me, that is about 2 cals per min and 120 cals an hour. Using your numbers, if my TDEE is for the day, is 2000 after doing a 400 cal burn, my TDEE without exercise would have been 1720.
  • Ascolti_la_musica
    Ascolti_la_musica Posts: 676 Member
    Mine has been pretty much spot on. I've been using it for about 2-3 months. My calories in/out line up almost perfectly with my weight loss. I also use the FitBit Aria scale to track my weight and body fat percentage.

    Do you wear it all day, or just when you exercise? Do you spend much time sitting at your desk? I think a lot of people underestimate the amount of time we spend at the desk, on the couch, watching TV, etc. On the days when I do not wear it, I have actually noticed it will give me a HIGHER estimate for the day, with a note about not receiving much information from me that day.

    I love it, and tell everyone who will listen that they should get one. If nothing else, those little badges are extremely motivational! :-)
  • LaurenAOK
    LaurenAOK Posts: 2,475 Member
    Thanks for the input everyone! Interesting thought that it would actually be 1720 for the day without exercise, that would make more sense.

    I do track my exercise separately here on MFP, and I have the two linked up. So even if it doesn't do a good job of picking up exercise activity it should still end up with the right numbers.

    I do spend a decent amount of time sitting around every day but as I mentioned I also do a fair amount of errands, cooking, etc.

    I did say that I was losing more slowly than expected but I also said that sometimes I lose more quickly than expected, which is true. Maybe for now I'll just use some average of the MFP and Fitbit estimates. Thanks again for all the feedback.
  • SpecialSundae
    SpecialSundae Posts: 795 Member
    My FitBit/HRM burns are way higher than MFP. I've been tracking for a while and some days my average TDEE is around 2500 calories per day (some days 2200, a few 3000+) and my weight loss is pretty much bang on what it should be.
  • lizzardsm
    lizzardsm Posts: 271 Member
    I have a bodymedia fit (which I've read is supposed to be the most accurate one on the market) and I have very similar results to you. I'm 5'4 and in the low 140's. I lift and take the subway to work 3x/week but not too much cardio other than walking around. My TDEE w/o exercise is usually around 1650-1750 and with exercise is in the low 2000's. You may have just been over estimating!
  • LaurenAOK
    LaurenAOK Posts: 2,475 Member
    I have a bodymedia fit (which I've read is supposed to be the most accurate one on the market) and I have very similar results to you. I'm 5'4 and in the low 140's. I lift and take the subway to work 3x/week but not too much cardio other than walking around. My TDEE w/o exercise is usually around 1650-1750 and with exercise is in the low 2000's. You may have just been over estimating!

    Good to know! Sad to think maybe I should be eating a little less, but I'll accept it :frown:

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