Differences in daily calories allowance totals

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Tania_181
Tania_181 Posts: 100 Member
Hi all, I use the calories provided by MFP, with adjustments for exercise from my Fitbit charge 2. I usually ignore the calorie information on Fitbit other than the daily/weekly amount burned. But, I noticed recently that the total calorie allowance for the day on the Fitbit app is still less at the end of the day then on MFP, sometimes indicating I've gone over my calories for the day when MFP says I'm within. Can you explain what causes this?

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  • Tania_181
    Tania_181 Posts: 100 Member
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    Edit.
    I reviewed the calories inputs on Fitbit for yesterday vs my MFP diary and found that it had two entries for my 'afternoon snacks', one with the actual figure and another showing an additional 200+ calories. Strange goings on!
  • Francl27
    Francl27 Posts: 26,372 Member
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    MFP always gives me an extra 150-200 calories that disappear overnight. Trust your Fitbit 'calories left' information (assuming that you have the same weight loss goal set up for both).
  • heybales
    heybales Posts: 18,842 Member
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    Both accounts estimate remaining calories for the day.
    If you hit the couch and then go to bed at say 8pm, you have 4 hrs at basically BMR level burn rate.

    MFP estimates at a rate based on your selected activity level.
    At minimum Sedentary, you are given a rate of 1.25 x BMR though, so it's always estimating high. That method works fine with no tracker, what you've seen is issue with tracker.

    Fitbit estimates at a rate based on 2 options.
    Historical like MFP based on avg weekday or weekend daily rate.
    Or Sedentary barely above BMR which is more correct at the end of the day like that, but obviously way off the earlier you start.

    If the food syncing is correct through the day, the Fitbit set to Sedentary will likely give a better view of remaining calories to meet the end of day goal.

    Which on MFP should leave you in the green.

    If you hit the couch and go to bed about the same time - that amount is always about the same, so you'll get used to just leaving that much in the green.
    Then when MFP corrects itself with newer Fitbit info the next morning, it'll show you met your goal.
  • Kathryn247
    Kathryn247 Posts: 570 Member
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    heybales wrote: »
    but obviously way off the earlier you start.
    I'm having trouble understanding this. I use an Alta HR and I'm set to sedentary (desk job). MFP gives me 1200 calories/day plus around 200 for my Fitbit calorie adjustment. I try to eat back half of my exercise calories, so half of whatever it gives me over 1200.
    I go for a run or walk in the evening that I track with MapMyWalk or the C25K app. When I'm done, the calories for that workout sync to MFP and are subtracted from my Fitbit calorie adjustment. A few minutes later, MFP adjusts again, giving me a couple hundred more calories, which I fgured were from my run/walk. I recently realized that the next day, those couple hundred calories disappeared again, so I've been eating closer to all of my exercise calories than half of them. I exercise late in the day (like 7 or 8pm), so why does it do this? What can I do to make it more accurate? Thanks!
  • heybales
    heybales Posts: 18,842 Member
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    So that 1200 daily goal is if you were indeed sedentary - less than 4000 steps each and every day is what it usually works out to be.

    If you are more active than that, exercise or just more active than sedentary - you eat more.

    Life lesson there.
    You do more, you eat more.
    You do less, you eat less.

    In a diet, tad less in either case.

    So while the adjustment shows up under Exercise for MFP to do the math with it correctly - it is not necessarily exercise.
    You could do no exercise and be very active and have a big adjustment.
    You could do big workout and then lazy rest the day and have no adjustment.

    If you are willing to trust MFP, and you selecting from 4 rough activity levels - why not trust MFP trying to correct itself by means of a more accurate method - the Fitbit?

    So the workout doesn't subtract from the adjustment, but it is in the math with the adjustment.

    Let's pretend you have 500 cal deficit daily, since you didn't mention that and it's needed.
    So if 1200 eating goal then 1700 daily burn estimate at sedentary. You need MFP's estimate of daily burn, not the eating goal actually.

    So if Fitbit reports you burned 1900 including the workout, then

    Fitbit 1900 - MFP 1700 = 200 cal adjustment.

    Base eating goal 1200 + 200 cal adjustment = 1400 new eating goal.

    You manually log a workout or sync one in from 3rd party besides Fitbit, say 300, then

    Fitbit 1900 - MFP 1700 - 300 exercise = neg 100 adjustment.

    1200 - 100 adj + 300 = 1400 new eating goal.

    But then within minutes that workout syncs over to Fitbit and replaces whatever it came up with for calories for that chunk of time.
    Say 200 originally, replaced with 300 now.
    And then that syncs back over to MFP.

    Fitbit 2000 - MFP 1700 - 300 exercise = 0 adjustment.

    Eating goal 1200 + 300 exercise = 1500 new eating goal.

    Now, if MMW was more accurate than Fitbit for the calorie burn - then the sync corrected the Fitbit stats, and you are correctly eating more.

    Notice in all cases - the deficit of 500 is still in place.

    There is absolutely no need to cut the exercise calories, or what is more likely merely increased daily activity calories - in half.

    That advice is incorrectly thrown out by people that don't understand how the system works - and it doesn't apply when syncing in better estimated data.
    This is not the database calorie burn, which frankly for a specific speed would actually be correct.

    Depending on when you look at those stats - since you are dealing with 3 different syncs, those values will change.
    And the way Fitbit syncs to MFP - the daily burn must go up by 100 before it sends a new value over.
    So if the sync made the daily burn go down by say 100 - then you'll have to wait a good chunk of time before the new daily value comes over for MFP to correct itself.

    And then it'll be lower.

    As to making that better, if Fitbit has the best stride length for you, and distance of walk is correct - then it's calorie burn is going to be more accurate unless there was just lots of up and down inclines. It doesn't know incline and increased calorie burn.
  • zoeysgood
    zoeysgood Posts: 4 Member
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    Thank you for that explanation! I am reluctant to use all my exercise calories, and have been losing slowly. I too am on a 1200 calorie diet as I sit 4 days a week at a desk (10 hour days). I do however walk a lot and garden and do yoga, so do get famished on the 1200 calories. Any more suggestions are welcome!
  • heybales
    heybales Posts: 18,842 Member
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    zoeysgood wrote: »
    Thank you for that explanation! I am reluctant to use all my exercise calories, and have been losing slowly. I too am on a 1200 calorie diet as I sit 4 days a week at a desk (10 hour days). I do however walk a lot and garden and do yoga, so do get famished on the 1200 calories. Any more suggestions are welcome!

    Use the tool correctly.
    Using a tool wrong at best means it's ineffective. At worst you'll get hurt. No difference here.

    If you are syncing in a Fitbit - eat what MFP says to eat. Which is NOT going to remain 1200, unless you truly have a sedentary day.

    And just having a desk job doesn't mean you are on average Sedentary - there are 3 other days of the week there.
    If you have kids or pets or family and house responsibilities you care for after work - you are Lightly Active.
    With something like Fitbit synced in that would be corrected.

    If no Fitbit or similar - then be honest and change your activity level to Lightly Active.
    Unless you log any walking that was purposely done like exercise, and the garden and the yoga.
    If Lightly Active is set, merely log the yoga and purposeful exercise walks with known distance and time - that's accurate in the database.

    Then eat your goal as given - which will NOT remain 1200, because you are no longer Sedentary.

    Also take a reasonable weight loss speed - you probably didn't gain it fast, accept losing it slow too.
    If set to 2lb weekly, which may be nice, but unreasonable if less than 50 lbs to lose. Change it to 1 lb if 15-30 lbs left to lose.
  • Kathryn247
    Kathryn247 Posts: 570 Member
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    heybales wrote: »
    Thanks for the detailed response, haybales! Do you know why my exercise calories change overnight? Yesterday evening I synced my Fitbit to MFP, and MFP told me I earned about 300 extra calories from exercise. I ate 130 of those (I wasn't really hungry). This morning when I look at yesterday's entry, it says I only earned 78 calories from exercise yesterday. So the 130 calories I ate actually put me over for the day. Why does it do that? Which is correct? I'd be happy to eat all of my exercise calories, but not if the next morning MFP tells me it put me over for the day.
    Also, where do I find my estimate of daily burn? I just made my diary public. I'm 152lbs, 5'2", set to sedentary and lose 1lb/week. It says I will actually lose .8lbs/week at 1200 calories (which is fine).
    Thank you!

  • heybales
    heybales Posts: 18,842 Member
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    While that Adjustment is found under Exercise diary - it is not just exercise, to be clear.

    Could be very active day no exercise and big adjustment up.
    Could be big workout but lazy day and no adjustment up.

    Since shorter and MFP stops the subtraction for weight loss at 1200, if you get positive adjustments each day exercise or not - I'd suggest increasing Activity Level to Lightly Active you might be.
    And enable Negative adjustments in Food settings just in case days you aren't.
    That will allow the full 500 deficit that is appropriate, until down at 15 lbs left to go and you should switch to 250.

    That will cause less adjustment though for correction. And some days probably get negative calories.

    And cause the effect you observed at night to be bigger - but still something to figure out.

    So MFP is calculating rest the day until midnight at the same rate as all day. Which is expected daily calorie burn / 1440 = per min burn.

    Of course when you hit the couch and go to bed, Fitbit is recording the more correct BMR level burn, which replaced the MFP higher level of incorrect burn, the next morning on sync.

    Fortunately if you usually hit the couch and then bed about the same time - that difference will always be about the same.
    Appears that could be the 130.
    So prior night stay 130 in the green.
    Next morning after adjustment, it'll be hitting target.

    Now - that 130 estimate is based on time of last sync, like the last time you looked and saw 300, could have been mere minutes before a sync was going to happen, and it would have corrected right then and given you much better idea.

    You can look at the details on that MFP adjustment - and see the time of last sync, and number of calories then.
    Fitbit only sends new data when the daily burn goes up 100 more calories than prior sync. Which if sitting, would likely take you 1.5 hrs. Keep that in mind.

    As to what MFP's estimated daily burn is, look at yesterday's Adjustment details, it states what MFP Calories Burned is. That's their estimate of daily total to do math with.
  • Christine_72
    Christine_72 Posts: 16,049 Member
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    @Kathryn247 I'm set at sedentary and i lose around 60-70 calories every night. When i was set at lightly active, that went up to around 200 calories :weary: Because i go to bed early i just leave my settings at sedentary.