How accurate is FitBit TDEE (HR monitor version)?
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DomesticKat wrote: »Just looking back until May, I have some questions. The recipes you log, are those generic entries or are you adding them to your recipes yourself? Some appear to be generic. How are you calculating a serving for a recipe? I see some entries that aren't weighed. Things like cake or cinnamon buns that are entered as a partial serving. I also see some entries missing for dinner or lunch. Did you not eat meals on those days? I see that you're eating out at restaurants or fast food as well. Those can be off since you have to estimate the calorie content. I see days where you're over on calories as well as under, so there are some issues with consistency. Those are all things I would recommend tightening up before jumping to not losing at 1400 calories.
The recipes are created using the recipe importer (if it is a website) or the calculator (if it is from a cookbook). I try to adjust the recipes so they match the actual ingredients I am using (brands, etc.). It is hard to get the serving sizes exact except for things that are individually portioned, such as stuffed peppers. etc. That is something I do struggle with since we cook most nights.
If you see a partial, like .25 slices of cake, that's because I only ate a bite or two.
I didn't realize I had missed logging some meals in there. That may have been while travelling. I assume the fast food entries should be close to accurate since they have to post the calorie counts. I have a lot more trouble when I am going to a nice local restaurant to try to find reasonable entries that are close enough.
I will work on tightening up my logging some more. Thank you for taking the time to look through my food diary and give concrete suggestions! I appreciate it.0 -
My Fitbit Charge 2 has me right on track. If you think it's overestimating your burn, try eating fewer for a while and see if that works.
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Any device that estimates calories is measuring (something) and using research-based formulas to estimate calorie burn. It isn't measuring calorie burn. The implication is that the estimate is only as good as (1) the quality of the formulas and their implementation, and (2) how close your personal calorie burn is to the people in the underlying research with respect to the (something) measured.
That (something) may be heart rate, it may be arm motion, it may be steps - doesn't matter. It's still an algorithm estimating calories based on statistical studies.
The nature of statistics suggests that these devices will be accurate for some (for most, if the algorithms and research are sound), because most results will be near the mean (average) of the study population. For some, they will be noticeably but not severely inaccurate. For perhaps a tiny, tiny few, could possibly be quite inaccurate (possibly in either direction).
Heart rate isn't really a great proxy for calorie burn, especially in a device that doesn't know your true maximum heart rate (because age based formulas are inaccurate for quite a few people. Heart rate also isn't a great proxy for workouts other than steady state cardio, though if some devices let you identify the workout type they may do a little better.
Looking purely at probabilities (no personal insult intended at all), it's more likely that someone's results are not as expected because of some kind of logging problem, because overlooking something in that realm is pretty common. The device being way, way off - in what others report as an accurate device - is a lower-probability explanation, because well-designed devices are likely to be within a reasonable range of accuracy for a lot of people. I hope this may help you understand why people are picking at that issue, though you're quite certain you're logging meticulously.
So, yes, your TDEE could be off. But being 100% certain everything else is accurate may be helpful (if sort of annoying), since you'd like TDEE to be higher than 1400 (and 1400 seems very low for your stats).
Best wishes!5 -
DomesticKat wrote: »Just looking back until May, I have some questions. The recipes you log, are those generic entries or are you adding them to your recipes yourself? Some appear to be generic. How are you calculating a serving for a recipe? I see some entries that aren't weighed. Things like cake or cinnamon buns that are entered as a partial serving. I also see some entries missing for dinner or lunch. Did you not eat meals on those days? I see that you're eating out at restaurants or fast food as well. Those can be off since you have to estimate the calorie content. I see days where you're over on calories as well as under, so there are some issues with consistency. Those are all things I would recommend tightening up before jumping to not losing at 1400 calories.
The recipes are created using the recipe importer (if it is a website) or the calculator (if it is from a cookbook). I try to adjust the recipes so they match the actual ingredients I am using (brands, etc.). It is hard to get the serving sizes exact except for things that are individually portioned, such as stuffed peppers. etc. That is something I do struggle with since we cook most nights.
If you see a partial, like .25 slices of cake, that's because I only ate a bite or two.
I didn't realize I had missed logging some meals in there. That may have been while travelling. I assume the fast food entries should be close to accurate since they have to post the calorie counts. I have a lot more trouble when I am going to a nice local restaurant to try to find reasonable entries that are close enough.
I will work on tightening up my logging some more. Thank you for taking the time to look through my food diary and give concrete suggestions! I appreciate it.
It's not any one day that's a big deal, it's the long-term trend that's important because high days can wipe out low days over the course of a week, month, and year. When there are consistency issues over a long period of time, that will influence your overall rate of loss.
Restaurant calorie counts can be off unless they're weighing and measuring every component of the dish each time they're making it.
For the recipes, it's fine to create them yourself in the recipe builder but try not to use generic entries because you have no idea how different from your recipe they actually are and what ingredients they included. When you build your own recipe and are using a single cooking vessel, weigh your cooking vessel empty and write that down. Then once your dish is completed, weigh the finished dish and subtract the empty weight of the cooking vessel from it. That's your number of servings to enter in the recipe in grams. Then when you go to log it, weigh out your portion and enter that as your serving size. It's not going to be 100%, but it's better than eyeballing portions. Do that for whatever entree and sides you make.2 -
TavistockToad wrote: »TavistockToad wrote: »janejellyroll wrote: »
No, my weight stays about the same at 1,400. If I go above that, say a couple of splurge days of 1600-1800, then, yes my weight goes up. It usually rebounds back to about the same level after going back to strict 1,400 for a few days.
That seems pretty low. Are you using a food scale for all your solid food?
Yes, I weigh meat in ounces since most of the entries use ounces, and everything else in grams, including hummus and shredded cheese! Except of course when I eat out, which is usually one night a week. But I usually get a burger with no bun and a salad with no dressing, so I don't think my logging could be off enough from that to wreck a whole week. I'm just feeling very frustrated at the moment. The biggest ? would probably be the wine I have with dinner, but if my TDEE is accurate, I'd have to be drinking two extra bottles of wine a week to account for the calories mismatch, which is definitely not the case.
You don't log the wine?
Of course I log the wine. But I pour it into a glass. I don't weigh it. So there might be a variance if I am logging a glass as five ounces but in fact it is six ounces.
Surely you can figure that out by how many glasses you get out of a bottle...? It's not that difficult a calculation....
Yes, there are 5 glasses per bottle. So if I drink half a bottle of wine, I log 2.5 glasses. I'm saying it might not be exact, but it should be pretty close. You are kind of treating me like an idiot here.
If I am maintaining at 1,400 calories a day but my FitBit says my TDEE is 2,400 calories a day, then either my consumption numbers are wrong or my TDEE is wrong. I am a very tight logger, so I'm theorizing that my TDEE is not correct, and this post was to see if anyone else had encountered similar issues.
I was responding in kind to your attitude.
And as your other identical thread has shown, you're not accurate in your logging.2 -
If the Fitbit is mistakenly using HR-based calorie burn for daily activity level of stuff - it's inflated calorie burn.
It attempts in first week to figure out your resting HR, and non-activite HR, and it tries to figure out that point where it should switch from more accurate step-based calorie burn to HR-based.
But if on some meds, or genetic, and you just have a high HR in general - it could be including a whole lot more gentle activity time as exercise level and getting inflated HR.
If that is the case then to have HR on all the time won't be useful as far as estimated calorie burn goes. Perhaps still useful if you are supposed to monitor your HR thru the day. If not, turn it off except for exercise.
You could also have an incorrect stride length setting for walking, and it's seeing a lot more distance than you do for normal daily things, and more distance is more calories - so inflated again.
Walking stride length should be set for avg daily pace, not grocery store shuffle, not exercise level pace - in the middle. That way it can adjust either direction as it needs to with chance of accuracy.
It does not attempt to estimate calories burned from eating food, or standing with no steps - so underestimated there.
Potential accuracy can be improved.
Some workouts too are not going to be good with either step-based or HR-based calorie burn - like lifting, or swimming obviously. Intervals is bad for HR, rowing is bad for step-based, ect.
But if workout is 20 min weekly with otherwise lots of activity - doesn't matter.
If it lots of time weekly and otherwise very sedentary - could matter much more.
And even with all that, it's accuracy may remain off by some %, which is good to know, because then as seasons change and your activity level may change, you can keep up with that potential % off being the same and adjust as needed.
Instead of taking 30 days to discover, then 30 days to see if adjustment was correct, and by then 30 good days before season changes again!3 -
Mine has always been accurate for me. It helped me lose the last 15 lbs, and maintain my weight pretty easily for 3+ years by trusting and eating back the exercise adjustments. I’m 5’2 and 118 and average 12-15k steps a day, my FitBit estimates my TDEE to be about 2200. For what it’s worth...1
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My Fitbit is very accurate, as in my food log + burn numbers from Fitbit match my weight loss.
How long have you had your Fitbit? My boyfriend got one very recently and the numbers were all over the place for the first couple of weeks, before they sort of adjusted into place.
That being said, your numbers sound pretty high compared to mine. I’m 5’8”, weigh 200 (that’s my barrier!), average around 9000 steps and my burn average is at 2500-2600. Sure, you take more steps, but I’m significantly heavier, so I carry a heavier load around all day.0 -
I look at about a 6 week rolling avg because things are always changing. I am in maintenance. 5'1+ 59 yo around 99 lbs. Fitbit gives me a 1345 base for now (which is where i set MFP) and then I avg around 635 more cals per day due to activity. The ones I get from a specific exercise I usually accept 100%. The ones I get from the fitbit adjustment I think are a little inflated so I will usually go with 80% of those. If you are trying to lose, I agree that your #s seem very inflated. That all said, I don't really like to adjust cals on a daily basis because I like to have energy for my longer workouts before and not after. So, I stick around 1900 to 2K cals a day and that seems to level me out. When I was losing I never ate back any exercise cals and just put myself at a deficit which gave me about a 1 pound per week loss without trying to calculate TDEE manually. I did use a chart which said TDEE would be around 1800. That was low but it could just be summer right now. Again in maintenance rolling avgs become more significant.
To me, every individual will be unique so altho MFP and Fitbit give estimates and hopefully stay consistent, you have to monitor YOUR #s and go from there. They are great tools to help of course.0 -
How old are you....If I do not do any exercise my TDEE is very low as my BMR is about 1400, and I do not have PCOS. Fitbit will not know you have PCOS, which I believe, but may be wrong, might slow down your metabolism.
When you enter foods, do you check the entries you are using are correct, that could make a big difference.0
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