Fitbit

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cozaican
cozaican Posts: 3 Member
in Fitness and Exercise
Is anyone else just as confused as I am in regards to the extra calories that fitbit gives you? Have read pages and pages and am no further ahead then when I started.

MFP gives me 1710 calories a day

But on my fitbit I get calories at 2929 a day.

I dont know if I should be eating back the calories or not.

My weight not moving so can someone please enlighten me?

Replies

  • elephant_in_the_room
    elephant_in_the_room Posts: 145 Member
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    No useful answer here, only that I've recently tried wearing a Garmin Forerunner 310XT for 24 hours, with chest strap, in theory it should be way more accurate then a fitbit which can't know your heartrate that well.
    It counted almost 4000 calories... For an average-height 45yr woman with BMI 24 with a sedentary job 10 hours a day and, okay, three quarters of an hour of exercise in between.
    I guess the 4000 calories are about 2000 too much, and the thing is somewhere in dreamland.
    I would never eat them back, at least not think that I stay under my calorie limit that way.
    Now the fitbit is meant to be less accurate than a HR with chest strap, and so I wouldn't believe the 2929 either.
  • pinkraynedropjacki
    pinkraynedropjacki Posts: 3,027 Member
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    No useful answer here, only that I've recently tried wearing a Garmin Forerunner 310XT for 24 hours, with chest strap, in theory it should be way more accurate then a fitbit which can't know your heartrate that well.
    It counted almost 4000 calories... For an average-height 45yr woman with BMI 24 with a sedentary job 10 hours a day and, okay, three quarters of an hour of exercise in between.
    I guess the 4000 calories are about 2000 too much, and the thing is somewhere in dreamland.
    I would never eat them back, at least not think that I stay under my calorie limit that way.
    Now the fitbit is meant to be less accurate than a HR with chest strap, and so I wouldn't believe the 2929 either.

    One question..... why did you wear it for 24 hours? It's not meant for that at all. It's actually only meant for exercise.
  • pinkraynedropjacki
    pinkraynedropjacki Posts: 3,027 Member
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    OP..... forget the cals fitbit gives on their site..... they get that wrong... but if it gives you extra.... eat them if you want. I get over 1000 extra sent over from fitbit to here & eat most of them back, I still lose weight. I have me set to 2000 cals here, fitbit have me at 2500 for some reason & I can't get it to go lower.

    Only take what extra you get on here. Fitbit is kinda accurate in terms of the calories, but only the extra ones sent here really count.
  • callas444
    callas444 Posts: 261 Member
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    Mine gives me gobs of calories back. It is my choice not to eat them most of the time. It doesn't make sense to me to eat 2,500 or so calories instead of my 1,600 current goal. I'm easily losing 10 pounds a month without eating the exercise calories. This is without being hungry. If you are physically hungry, eat.

    If you exercise vigorously, you may need to eat some of the calories just to keep your body going. I don't. I just live and walk a little. So my experience may differ from yours.
  • elephant_in_the_room
    elephant_in_the_room Posts: 145 Member
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    No useful answer here, only that I've recently tried wearing a Garmin Forerunner 310XT for 24 hours, ....

    One question..... why did you wear it for 24 hours? It's not meant for that at all. It's actually only meant for exercise.

    That's no good excuse. The Garmin Forerunner 310XT uses the FirstBeat calorie calculation algorithm which uses the variation of the interval between heartbeats and is in theory accurate to 15%. I don't see any good reason why that algorithm should work any differently during shorter and longer periods, higher or lower heartrates. If it can't estimate my calories correctly at resting heartrate, why should it be accurate during interval training when the heartrate goes up and down? Where would the accuracy start? How can it be accurate over a 10hr bike ride? Granted when I only wear it for half an our during exercise, the error won't be that obvious, it will just always overestimate my calories.
  • LaserMum
    LaserMum Posts: 133
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    OP, you might find that that's the total calories you're expending in a day. If you then take off the calorie deficit you've set for you should be in the right range.

    I have a FitBit One and I've never had any problems, although I do think it might overestimate the calories burned a bit!

    I have both MFP and FitBit set for a 1000 calorie deficit and a sedentary lifestyle. MFP gives me 1200 calories and FitBit gives me 1139 so not much difference. I then eat back all my exercise calories and generally end up being able to eat about 2000 calories. I reckon that, at 1000 deficit, even if FitBit is overestimating the exercise calories, I still have a good deficit of over 500 calories.

    Also, I think FitBit personalises it by default. So if you've been very active in the past, it will allow you extra calories as it expects you to continue at that level of activity. I've changed mine to sedentary so it will only add additional calories as I do the exercise.

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