Differences in Fitbit vs MFP calculations!

andy_dang
andy_dang Posts: 3 Member
edited December 1 in Social Groups
Hi everyone!

Just as a foreword, I read through the syncing calculations sticky pretty thoroughly before posting this.

Anyways, before discovering MFP, I used the Fitbit app for logging food. It worked okay but many days I was in the yellow (below budget) and a few days I was in the red (above budget). I was still losing weight, but at a slower rate than it expected it to be.

However, when I switched to MFP I started logging food and exercises on the app to sync and recalculate with the Fitbit app. I've only been using the app for about two weeks, and I'm losing weight at a slightly slower rate than with the Fitbit (but then again, I have been to Cheesecake Factory three times within that period, haha).

That's all fine and dandy, but when I checked back in on the Fitbit app ALL of the days using MFP are red, over budget days! I have the same deficit on both (750 calories, 1.5 lbs/week). Is MFP over estimating how active I am? What would be the best way to log the food and exercises, or should I just keep doing what I'm doing?

Sorry for the lengthy post but thank you for any help!

Replies

  • NancyN795
    NancyN795 Posts: 1,134 Member
    There could be several things going on. One thing to check is whether the meal summaries that are transferring over from MFP to Fitbit aren't getting messed up. You should only have one meal summary for Breakfast, Lunch and Dinner. Other meals can get lumped into "Anytime" depending on how you have things set up and named, but you should still only get one summary per meal. One intermittent bug I've been seeing more often recently is multiple meal summaries for the same meal. Usually, one matches what I've logged on MFP and the others don't. I just delete the duplicates, making sure I keep one that matches.

    I log all my Food on MFP and all my exercise in Fitbit. I then use MFP to tell me how many calories I can eat. However, I try to keep Fitbit's meal summaries correct because I will occasionally go to my Fitbit profile page (on the website) and use the calories in vs calories burned numbers there to compare my expected weight loss with my actual weight loss. That can tell me how accurate I've been at food logging and/or how accurate my Fitbit is for me.

    MPF doesn't really estimate how active you are. It takes your word for it (the activity level you selected). However, with a Fitbit, it doesn't really matter which level you pick, as long as it works for you because you end up with the same number of calories to eat at the end of the day. All that your MFP activity level does is change how many calories you start with and then how big a Fitbit Calorie Adjustment you get later.
  • andy_dang
    andy_dang Posts: 3 Member
    NancyN795 wrote: »
    There could be several things going on. One thing to check is whether the meal summaries that are transferring over from MFP to Fitbit aren't getting messed up. You should only have one meal summary for Breakfast, Lunch and Dinner. Other meals can get lumped into "Anytime" depending on how you have things set up and named, but you should still only get one summary per meal. One intermittent bug I've been seeing more often recently is multiple meal summaries for the same meal. Usually, one matches what I've logged on MFP and the others don't. I just delete the duplicates, making sure I keep one that matches.

    I log all my Food on MFP and all my exercise in Fitbit. I then use MFP to tell me how many calories I can eat. However, I try to keep Fitbit's meal summaries correct because I will occasionally go to my Fitbit profile page (on the website) and use the calories in vs calories burned numbers there to compare my expected weight loss with my actual weight loss. That can tell me how accurate I've been at food logging and/or how accurate my Fitbit is for me.

    MPF doesn't really estimate how active you are. It takes your word for it (the activity level you selected). However, with a Fitbit, it doesn't really matter which level you pick, as long as it works for you because you end up with the same number of calories to eat at the end of the day. All that your MFP activity level does is change how many calories you start with and then how big a Fitbit Calorie Adjustment you get later.

    Thanks! But I've checked all you suggested an everything is all clear.

    For example, MFP says I can still eat 39 more caloires today. Meanwhile, Fitbit says I'm 329 calories over budget...as in my deficit is only 421 vs 750. At this point, I'm really confused on which app to rely on how much I should eat, because each have very different data.
  • heybales
    heybales Posts: 18,842 Member
    And is the time of your post really the time of those figures - meaning almost 3 hrs to midnight?

    Fitbit is probably set to sedentary - and on Fitbit that means barely at BMR, which could indeed be true for 3 hrs before midnight.

    MFP if set to sedentary is actually BMR x 1.25 - so much higher rate of burn for those 3 more hrs.

    Also - look at the MFP stats on that Fitbit calorie adjustment - they have slowed their rate of syncing - it may not even be the same time you are looking on Fitbit.
    So it could be looking at 4-5 more hrs actually.

    By the end of the day they will match, but sadly MFP getting syncs from Fitbit is infrequent enough to screw up my evening estimates.

    Once you go for enough days - you'll learn about what is right to use.

    Like the MFP estimate for those remaining 3 hrs is inflated to reality of sitting/sleeping - so if you met MFP eating goal at 9 pm, the next morning with newer Fitbit data, MFP would discover you didn't actually burn as much, and therefore you went over their adjusted eating goal.
    But that will always be the same per hour - so it's easy to figure out how much to leave in the green depending on the hour.

    IF, IF - MFP has a recent sync from Fitbit to work with.
  • NancyN795
    NancyN795 Posts: 1,134 Member
    If you look at a previous day and MFP says you were right on target and Fitbit says you were way over your calories, then something has to be off. As I said in my previous post, my first go-to is duplicate meal entries because normally mine match pretty closely when I look at a previous day. (They never match until the end of the day.) However, if there are no duplicate meal entries then either the settings are different between the two programs (height, weight, gender, age) or there's a new bug. I guess I'd try re-entering my stats in both programs and resetting my weight loss goal as well. There have been bugs where the displayed number looked right but an incorrect number was actually being used. (As I recall this was with weight on Fitbit.) Re-entering the value would fix it.
  • Christine_72
    Christine_72 Posts: 16,049 Member
    I've been getting duplicate meal entries every single day this week :angry:
  • shadow2soul
    shadow2soul Posts: 7,692 Member
    andy_dang wrote: »
    Hi everyone!

    Just as a foreword, I read through the syncing calculations sticky pretty thoroughly before posting this.

    Anyways, before discovering MFP, I used the Fitbit app for logging food. It worked okay but many days I was in the yellow (below budget) and a few days I was in the red (above budget). I was still losing weight, but at a slower rate than it expected it to be.

    However, when I switched to MFP I started logging food and exercises on the app to sync and recalculate with the Fitbit app. I've only been using the app for about two weeks, and I'm losing weight at a slightly slower rate than with the Fitbit (but then again, I have been to Cheesecake Factory three times within that period, haha).

    That's all fine and dandy, but when I checked back in on the Fitbit app ALL of the days using MFP are red, over budget days! I have the same deficit on both (750 calories, 1.5 lbs/week). Is MFP over estimating how active I am? What would be the best way to log the food and exercises, or should I just keep doing what I'm doing?

    Sorry for the lengthy post but thank you for any help!

    What's your calorie goal on MFP before any adjustments are made from Fitbit?

    Your deficit on MFP might not be exactly 750 calories. Even though you selected that rate of loss, MFP has minimum calorie goals for men and women. Example:
    If I set my profile to sedentary, MFP thinks I will maintain on 1600. Well, 1200 is the minimum calorie goal for women. So even if I selected to have a 1000 calorie deficit, MFP would only give me a 400 calorie deficit since 1000 calories would take me below the 1200 minimum.
  • heybales
    heybales Posts: 18,842 Member
    Ohhhh, excellent reminder.

    And for OP before you ask - no the additional exercise calories doesn't give the full deficit potential.

    But Fitbit doesn't operate that way on either thing, it'll be more than willing to set too low, and you get the full deficit because of that.

    That's one of the benefits of picking an MFP activity level that is more honest to daily life rather than sedentary - may get the full deficit put to eating goal.
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