So confused about fitbit adjustment to MFP

321icandothis
321icandothis Posts: 6 Member
in Fitness and Exercise
Started using fitbit and MFP a week ago, and I feel like I need a fitbit guide for dummies.

My issue:

Yesterday, my calorie goal was 1970 for the day, by the end of the day I had eaten 2,160 calories. To level this out I did a fairly intense cardio exercise for an hour and burned 400 calories. So in my mind I was thinking, "awesome, with my 400 calories burned from my 2,160 calorie intake I should be set at around 1,760 calories for the day and then be able to have a little snack later."

I ended up not having a snack later, and by 11:30 pm it said I had gone around 200 cals over for the day? It had something to do with that fitbit adjustment that makes no sense. When I should have been around 1760 in reality? It was as if my fitbit didn't register that I had burned 400 calories with MFP but I clearly saw that they had synced together a minute ago.

One thing I'll mention: I don't log my cardio exercise on MFP because I thought fitbit took care of that. Does that have something to do with it?


Today I have burned around 100 cals walking around my school campus yet my calorie intake has gone up. Shouldn't it decline? Etc.
So confused.
If anyone could break it down in simple terms I would be so so so appreciative !!!!! I really want to understand because I like the idea of it all.

Replies

  • FatYellowDog
    FatYellowDog Posts: 5 Member
    In my experience, Fitbit isn't particularly good at tracking cardio if I'm not walking or running. If I do an activity that isn't tracked well by Fitbit (biking, workout DVD, treadmill, etc.), I enter it on the Fitbit site and let it cross over to MFP as part of the Fitbit sync. If you truly believe that your exercise calories are being under-represented, that may help things line up a little better for you.

    In the case of your calories going up after exercise, what's happening is this: you have a goal of 1700ish calories for the day. You eat that and then burn 100 calories exercising. Your net calorie intake for the day is now 1600. MFP says, "You should consume 1700 calories AFTER what you burn for exercise, so I'm going to increase your calorie goal to 1800 to make up for those calories you burned." That's why your calories are going up instead of down. Most people on MFP seem to ignore the calories added from exercise or only eat 1/2 of what MFP adjusts for.
  • kristinhowell
    kristinhowell Posts: 139 Member
    Fitbit estimates your calorie burn for the rest of the day depending on your activity so far. So if you are looking at around dinner-time, it may say you have 500 extra calories. But if you just sit around a while, it will take calories away because it expected you to be as active as you were earlier.

    Also, I log everything on MFP except my walks, runs, and hikes. Some cardio it tracks okay, some it doesn't. If you don't move a lot, it may not track it. Lots of jumping, and it may track it well.

    ETA: It may also have to do with your activity setting on MFP. If you have it set to lightly active, and you aren't walking around 7,000-10,000 steps, you may not be as active as you or MFP thought and won't be allowed as many calories as MFP may be giving you. Works the other way around, too.
  • DiamondRubyMom
    DiamondRubyMom Posts: 147 Member
    A couple of things i have noticed. First when your fitbit says you've burned 400 calories in an hour, remember you would have burned at least 60 of those calories sitting on the couch. So you need to mentally subtract those from the calories you think you should now be able to eat. Secondly fitbit seems to over estimate the number of calories i will burn in the evening. It also stops guestimating some time around 11pm and just reports your current number. All of which makes late night snacking confusing. Finally i agree that fitbit is only reliable for walking. A heartrate moniter would be better for any intense cardio. Feel free to friend me if you have more questions.
  • sodakat
    sodakat Posts: 1,126 Member
    Let's see if I can help explain it. My net calorie goal is 1400. If I sleep late and look at Fitbit shortly after waking, my calorie goal may say 1254 due to a negative adjustment. This is because Fitbit expects me to burn "X" amount of calories by then in order to meet my daily goal, based on my height, age and weight.

    On days I get up early and take a walk by the time I get home I may have "earned" a hundred calories or more, giving me a net of about 1500 at that point. As long as I keep moving throughout the day I will continue to increase my calorie total, minus any foods I eat of course.

    But if I take a walk then sit on my duff the entire rest of the day, well Fitbit has to eventually do a negative calorie adjustment because I did not move enough to justify the "lightly active" calorie burn I have input in both Fitbit and MFP.

    I have learned that as long as I am over 15,000 steps I will burn enough calories to allow me to eat a few hundred more than my 1400 net, or to lose a bit more than my expected pound per week (my choice on eating more or losing more).

    It takes a while to understand what your body requires in order to meet the net calorie goal you've set for weight loss.

    Do you have MFP set to allow negative calorie adjustments? Also, do you have Fitbit and MFP set to the same activity level and calorie loss goals.

    I've found that the weekly report from Fitbit is spot on in predicting my weight loss as long as I weigh all foods and log accurately. I find using Fitbit to be both motivating and fascinating.
  • 321icandothis
    321icandothis Posts: 6 Member
    Thank you all for the awesome advice! So cool to have such a helpful community.

    I understand better now. I think my problem was that I had done an hour of intense cardio (for me it was speed walking) once during the day and then the rest of the day I was at the library doing homework, not doing anything nearly as active as that one hour of cardio. So my calorie goal decreased etc.

    I think I'm getting the hang of it.

    Also, I have made sure my MFP and FB are set up to sedentary and I have allowed negative calorie adjustments. Everything seems to be working out now!

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