Need help figuring out your TDEE? Get a Fitbit.

jonnythan
jonnythan Posts: 10,161 Member
edited October 28 in Health and Weight Loss
Every day there are a dozen posts by people who can't figure out their TDEE and therefore have no idea how much food to actually eat.

There are a bunch of ways to estimate TDEE. Some of them are good. Some of them are not so good. All of them involve a whole bunch of guesswork and estimation.

My suggestion is to forget all that and just spend $60-$100 on a Fitbit. The method I used for a long time, to great effect, was to estimate BMR using an online calculator, multiply by 1.2 to get a sedentary TDEE, and simply add exercise calories on top of it. It was the exercise calories that were the huge question mark - where do I draw the line between exercise calories and sedentary activity level? How many calories did I burn while walking through the mall for a few hours shoe shopping? Etc.

I got a Fitbit at the beginning of February and have implicitly trusted it ever since. I add a few extra calories for things the Fitbit can't really estimate well, like strength training, but other than that I just have it on my waist and let it do its thing. It connects to MFP and just automatically and brainlessly tells me how many calories I have to eat.

There's a bit of a learning curve getting all the numbers to sync between the sites, but once it's set up it's kind of amazing.

And if you're wondering how accurate/effective it really is, let my results speak for themselves:

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Replies

  • Jonesie1984
    Jonesie1984 Posts: 612 Member
    thanks for the info. I was considering getting one just because they're pretty cool =)
  • luckyjuls
    luckyjuls Posts: 505 Member
    I would really like to buy one, but I've become a little confused with what it's measuring. Just to clarify, it's tracking how many calories you are burning sitting, standing, breathing, right? Not just when you are working out?

    Does it tell you how many calories you have burned just breathing throughout the day or do you have to plug it in and adjust your day from there?
  • jonnythan
    jonnythan Posts: 10,161 Member
    I would really like to buy one, but I've become a little confused with what it's measuring. Just to clarify, it's tracking how many calories you are burning sitting, standing, breathing, right? Not just when you are working out?

    Does it tell you how many calories you have burned just breathing throughout the day or do you have to plug it in and adjust your day from there?

    It's basically a continuous TDEE measurement. It just sits there on your waist calculating the total number of calories you've burned since midnight. It includes BMR as well as activity.

    It updates this information to MFP, which compares it to what it expects your TDEE to be, and adjusts your calorie goal accordingly.
  • micheleb15
    micheleb15 Posts: 1,418 Member
    I have the Jawbone UP and just this past week was finally able to sync with MFP. I have no idea where these numbers are coming from. How did you figure out the learning curve for syncing?
  • jonnythan
    jonnythan Posts: 10,161 Member
    Oh, they also sync wirelessly through many phones or through a computer with the adapter plugged in.
  • jonnythan
    jonnythan Posts: 10,161 Member
    I have the Jawbone UP and just this past week was finally able to sync with MFP. I have no idea where these numbers are coming from. How did you figure out the learning curve for syncing?

    I'm not sure how the Jawbone measurements work so I can't really say.
  • luckyjuls
    luckyjuls Posts: 505 Member
    I would really like to buy one, but I've become a little confused with what it's measuring. Just to clarify, it's tracking how many calories you are burning sitting, standing, breathing, right? Not just when you are working out?

    Does it tell you how many calories you have burned just breathing throughout the day or do you have to plug it in and adjust your day from there?

    It's basically a continuous TDEE measurement. It just sits there on your waist calculating the total number of calories you've burned since midnight. It includes BMR as well as activity.

    It updates this information to MFP, which compares it to what it expects your TDEE to be, and adjusts your calorie goal accordingly.

    Thank you for the quick response. Might go ahead and get one today.
  • micheleb15
    micheleb15 Posts: 1,418 Member
    I have the Jawbone UP and just this past week was finally able to sync with MFP. I have no idea where these numbers are coming from. How did you figure out the learning curve for syncing?

    I'm not sure how the Jawbone measurements work so I can't really say.

    Darn, I have read that they are about the same. I am getting ready to deactivate it because all of the numbers are different somehow. Thought maybe I am missing something. I agree though, it is a very usefull tool for knowing my actual TDEE. It's no where near what the calculations say.
  • jonnythan
    jonnythan Posts: 10,161 Member
    I have the Jawbone UP and just this past week was finally able to sync with MFP. I have no idea where these numbers are coming from. How did you figure out the learning curve for syncing?

    I'm not sure how the Jawbone measurements work so I can't really say.

    Darn, I have read that they are about the same. I am getting ready to deactivate it because all of the numbers are different somehow. Thought maybe I am missing something. I agree though, it is a very usefull tool for knowing my actual TDEE. It's no where near what the calculations say.

    Well I do suggest you stick with one or the other. MFP calculates "calories remaining" its own way based on the current number given to it by the other app/device.

    I would suggest you look at previous, completed days and compare the MFP target calories to the target calories given by the other app. If they're far apart, you may want to adjust one or the other.

    Let me give you a for instance. Looking at yesterday, MFP wanted me to eat 2073 calories. Fitbit wanted me to eat 1963 calories. That's because Fitbit is set for a 500 calorie deficit and I set a custom goal on MFP that's a little bit less than that. That's fine. They don't need to match up perfectly.

    The most useful thing for adjusting is how Fitbit's site shows me calories eaten versus calories burned by day. It also shows an exact calorie deficit on a daily basis. I look primarily at that to see how big of a deficit I'm running. If the deficit is too big I'll raise MFP's goal a bit. If the deficit is too small I lower MFP's goal a bit.

    Either way, stick with MFP for meal planning. Just adjust your MFP goal up or down to make sure you're running an appropriate deficit.
  • luckyjuls
    luckyjuls Posts: 505 Member
    Sorry, one more question.

    You said your Fitbit is set to give you a 500 calorie deficit. So when it told you to eat 1963 calories, you technically burned more during your TDEE, but the 1963 was with the deficit accounted for? And, when there was a difference between the Fitbit number and the MFP, once you syched, was the MFP number replaced by the Fitbit number?

    I must sound like an idiot, i'm sorry!
  • thanks for this. knowledge is power :)
  • srk369
    srk369 Posts: 256 Member
    Completely agree with OP. I love the weekly progress report that gives average calories burned. I put that in a spreadsheet every week since some weeks are more active than others and look at my 10 week average to set my TDEE. It's been working great. It also takes the calories I've consumed from MFP and gives you the total deficit for the week so you can see that you are on track for your intended loss. Love it!!
  • jonnythan
    jonnythan Posts: 10,161 Member
    Sorry, one more question.

    You said your Fitbit is set to give you a 500 calorie deficit. So when it told you to eat 1963 calories, you technically burned more during your TDEE, but the 1963 was with the deficit accounted for? And, when there was a difference between the Fitbit number and the MFP, once you syched, was the MFP number replaced by the Fitbit number?

    I must sound like an idiot, i'm sorry!

    Right. The Fitbit website says I burned 2463 calories yesterday. It has a little food planning section that I don't really use, but it says that I was supposed to eat 1963 yesterday.

    Here's how the MFP calculation works on previous days. I told MFP my age/height/weight, and activity level (sedentary). It then calculated that my before-exercise TDEE is 2040. I manually set my goal to 1650 calories. Fitbit then tells MFP "his actual TDEE yesterday was 2463." MFP says "oh OK, 2463 is 423 more than the 2040 I expected, so I'll add 423 to his goal." Therefore my MFP goal becomes 1650+423 = 2073.
  • micheleb15
    micheleb15 Posts: 1,418 Member
    Well I do suggest you stick with one or the other. MFP calculates "calories remaining" its own way based on the current number given to it by the other app/device.

    I would suggest you look at previous, completed days and compare the MFP target calories to the target calories given by the other app. If they're far apart, you may want to adjust one or the other.

    Let me give you a for instance. Looking at yesterday, MFP wanted me to eat 2073 calories. Fitbit wanted me to eat 1963 calories. That's because Fitbit is set for a 500 calorie deficit and I set a custom goal on MFP that's a little bit less than that. That's fine. They don't need to match up perfectly.

    The most useful thing for adjusting is how Fitbit's site shows me calories eaten versus calories burned by day. It also shows an exact calorie deficit on a daily basis. I look primarily at that to see how big of a deficit I'm running. If the deficit is too big I'll raise MFP's goal a bit. If the deficit is too small I lower MFP's goal a bit.

    Either way, stick with MFP for meal planning. Just adjust your MFP goal up or down to make sure you're running an appropriate deficit.

    Thanks. I've had the UP for a while now, but just recently MFP allowed them to be synced. I really wasn't sure what syncing was going to do, but I don't like the fact it messes with my calories.

    Yesterday, my daily burn according to UP was 1695, I eat 1600 a day total on MFP, however it gave me 364 extra calories from activities. My active burn for the day was 533 on the UP. No clue where the 364 came from. I eat 1600 no matter what and don't eat back calories burned.

    What I just wrote doesn't even make sense to me, so I don't plan on it making sense to anyone else. Thanks for attempting to help though!
  • jonnythan
    jonnythan Posts: 10,161 Member
    Well I do suggest you stick with one or the other. MFP calculates "calories remaining" its own way based on the current number given to it by the other app/device.

    I would suggest you look at previous, completed days and compare the MFP target calories to the target calories given by the other app. If they're far apart, you may want to adjust one or the other.

    Let me give you a for instance. Looking at yesterday, MFP wanted me to eat 2073 calories. Fitbit wanted me to eat 1963 calories. That's because Fitbit is set for a 500 calorie deficit and I set a custom goal on MFP that's a little bit less than that. That's fine. They don't need to match up perfectly.

    The most useful thing for adjusting is how Fitbit's site shows me calories eaten versus calories burned by day. It also shows an exact calorie deficit on a daily basis. I look primarily at that to see how big of a deficit I'm running. If the deficit is too big I'll raise MFP's goal a bit. If the deficit is too small I lower MFP's goal a bit.

    Either way, stick with MFP for meal planning. Just adjust your MFP goal up or down to make sure you're running an appropriate deficit.

    Thanks. I've had the UP for a while now, but just recently MFP allowed them to be synced. I really wasn't sure what syncing was going to do, but I don't like the fact it messes with my calories.

    Yesterday, my daily burn according to UP was 1695, I eat 1600 a day total on MFP, however it gave me 364 extra calories from activities. My active burn for the day was 533 on the UP. No clue where the 364 came from. I eat 1600 no matter what and don't eat back calories burned.

    What I just wrote doesn't even make sense to me, so I don't plan on it making sense to anyone else. Thanks for attempting to help though!

    If you go to your Exercise tab, you can click the "i" icon next to the adjustment and it'll show you exactly how it calculated the 364.
  • wannatangle
    wannatangle Posts: 80 Member
    Does the Fitbit also calculate accurately during exercise or would I still get that number from my heart rate monitor? I've been thinking about getting one. :)
  • jonnythan
    jonnythan Posts: 10,161 Member
    Does the Fitbit also calculate accurately during exercise or would I still get that number from my heart rate monitor? I've been thinking about getting one. :)

    IMO, heart rate monitors are terrible for calculating calories. That's a whole other rant though.

    Just look at the weight loss graphs in the OP to see how accurate the Fitbit is.

    It's not accurate for things where you're not on your feet, like cycling or swimming or rowing. You can just add those manually.
  • bacitracin
    bacitracin Posts: 921 Member
    I can't wait for my Fitbit Flex to get in!
  • luckyjuls
    luckyjuls Posts: 505 Member
    Sorry, one more question.

    You said your Fitbit is set to give you a 500 calorie deficit. So when it told you to eat 1963 calories, you technically burned more during your TDEE, but the 1963 was with the deficit accounted for? And, when there was a difference between the Fitbit number and the MFP, once you syched, was the MFP number replaced by the Fitbit number?

    I must sound like an idiot, i'm sorry!

    Right. The Fitbit website says I burned 2463 calories yesterday. It has a little food planning section that I don't really use, but it says that I was supposed to eat 1963 yesterday.

    Here's how the MFP calculation works on previous days. I told MFP my age/height/weight, and activity level (sedentary). It then calculated that my before-exercise TDEE is 2040. I manually set my goal to 1650 calories. Fitbit then tells MFP "his actual TDEE yesterday was 2463." MFP says "oh OK, 2463 is 423 more than the 2040 I expected, so I'll add 423 to his goal." Therefore my MFP goal becomes 1650+423 = 2073.

    Thank you SO much!
  • micheleb15
    micheleb15 Posts: 1,418 Member
    If you go to your Exercise tab, you can click the "i" icon next to the adjustment and it'll show you exactly how it calculated the 364.

    Thank you for this info. I am on day three of it syncing and never knew that it was added on the exercise tab. I'll figure it out.
  • Indiplanet
    Indiplanet Posts: 1
    I agree. Added fitbit use on January 21st - down 21 pounds since then - just by staying in the goal range of calories consumed.
  • Mia_RagazzaTosta
    Mia_RagazzaTosta Posts: 4,885 Member
    I :heart: my FB. I forgot to put it on one day and I felt like I was missing a limb.
  • da_bears10089
    da_bears10089 Posts: 1,791 Member
    One thing i've noticed with my fitbit, is i'm not sure of how accurate of a calorie count it can give for things like riding a bike. It doesn't have anything to do with my heart rate, doesn't pick up "steps" because there isn't enough of the walking motion, so how can i rely on that for how much i should be eating in a day? Right now, mine says i've burned 1000 calories from midnight until now.
  • tonytoo
    tonytoo Posts: 307
    The fitbit one estimates your TDEE just like every website does with your vital stats. Then it divides that by 24 and uses that value when you're not doing anything. It's just a glorified pedometer so it can only measure what a pedometer can. It does vertical too, which is a bonus.

    A heart rate monitor is way more accurate.
  • Bekahmardis
    Bekahmardis Posts: 602 Member
    Right. The Fitbit website says I burned 2463 calories yesterday. It has a little food planning section that I don't really use, but it says that I was supposed to eat 1963 yesterday.

    Here's how the MFP calculation works on previous days. I told MFP my age/height/weight, and activity level (sedentary). It then calculated that my before-exercise TDEE is 2040. I manually set my goal to 1650 calories. Fitbit then tells MFP "his actual TDEE yesterday was 2463." MFP says "oh OK, 2463 is 423 more than the 2040 I expected, so I'll add 423 to his goal." Therefore my MFP goal becomes 1650+423 = 2073.
    That's exactly what I did. MFP set my goal at 1200 (which is actually pretty close to where it *should* be with my goals) and then whatever my FitBit Flex tells MFP I've "earned" MFP adds back into my goal so i can eat back that exercise and still remain on target. So far, so good!!
  • jonnythan
    jonnythan Posts: 10,161 Member
    I :heart: my FB. I forgot to put it on one day and I felt like I was missing a limb.

    I had a mini panic attack when I went to play tennis one day without it. I tried to estimate the calories I burned later and remember how much of a pain in the butt it was to try to do that every time I exercised.

    The Fitbit takes away so much annoying guesswork it's unbelievable. I literally never have to sit around and try to calculate how many calories I may have burned playing racquetball or walking around the mall or whatever. It's very liberating, and that's why I started this topic.
  • Mia_RagazzaTosta
    Mia_RagazzaTosta Posts: 4,885 Member
    I :heart: my FB. I forgot to put it on one day and I felt like I was missing a limb.

    I had a mini panic attack when I went to play tennis one day without it. I tried to estimate the calories I burned later and remember how much of a pain in the butt it was to try to do that every time I exercised.

    The Fitbit takes away so much annoying guesswork it's unbelievable. I literally never have to sit around and try to calculate how many calories I may have burned playing racquetball or walking around the mall or whatever. It's very liberating, and that's why I started this topic.

    Agree!
  • heybales
    heybales Posts: 18,842 Member
    Right. The Fitbit website says I burned 2463 calories yesterday. It has a little food planning section that I don't really use, but it says that I was supposed to eat 1963 yesterday.

    Here's how the MFP calculation works on previous days. I told MFP my age/height/weight, and activity level (sedentary). It then calculated that my before-exercise TDEE is 2040. I manually set my goal to 1650 calories. Fitbit then tells MFP "his actual TDEE yesterday was 2463." MFP says "oh OK, 2463 is 423 more than the 2040 I expected, so I'll add 423 to his goal." Therefore my MFP goal becomes 1650+423 = 2073.

    ^^^ That needs to be posted as sticky somewhere because most just don't understand what it's doing with the adjustments.

    Manual eating goal doesn't even matter, I'm glad you spelled the math out.

    Of course, that concept is exactly what happens with the whole eating back exercise calories too that so many don't get either, but at least that math makes it easy to see.

    Great example.
  • ellen_kay
    ellen_kay Posts: 304 Member
    I have the FBZip and love it. It is another extension on me and I follow it regularly. I love that it gives me a target zone to lose 1lb a week. I input my food in MFP and let the FB tell me when to stop eating. Love it.
  • ozigal
    ozigal Posts: 173 Member
    I have a fitbit as well and I use trendweight.com for weight trends in the same way the OP does. I don't count any exercise that my fitbit doesnt register and my results are very similar to the OP.

    The way I see it, if I burn extra calories and fitbit doesnt pick it up... bonus! That's more weight lost not more food for my mouth :)
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