Super confused about negative calorie adjustments, my Fitbit and my HRM - HELP

You're a data person so I don't think I will lose you. This is how it works:

MFP estimates your daily burn for activity & BMR based on stats and activity level. For sake of this example, lets assume your daily # for MFP is 2400. MFP then assumes you'll burn 100/hour as there are 24 hours in the day. MFP can't tell slow hours from busy hours, they're all the same.

When you sync your Fitbit, MFP gets info on your actual burn. Lets say your BMR is 75 per hour. You wake up at 6am, you sync. Fitbit says you've burned 75 x 6 = 450. MFP expected 600, so you're -150 right now. You're behind. Then from 6am-7am you're around the house, getting ready for the day. At 7am Fitbit says your total is 545 so far. MFP expected 700, you're still behind. You go for a run from 7am-8am. At 8am Fitbit says you've burned 900 total. MFP expected 800, you're ahead by 100. And so on all day. Each time you sync, MFP takes what you've burned, compares to where you 'should' be and adds or subtracts.

So what happens when you log an activity? Lets say you logged your run from 7am-8am as 325 calories. MFP sees that you burned 325 for that hour, assumes 100/hour for all the hours with nothing logged, and says you will burn 2625 today. There are 16 hours left, so you should burn 1600 more. So when you sync Fitbit, and it says you've burned 900 by 8:00am, MFP says 900 burned + 1600 for the rest of the day: you're only going to hit 2500. You're behind target by 125.

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At the end of the day, if you really do burn 2500 its not a big deal. Whether you burn 2400 + 100 Fitbit adjustment or 2625-125 Fitbit adjustment its still 2500. The main thing is for you to be able to understand your #s and know what to eat. It can be rather confusing to log work in MFP and use the Fitbit and end the day with a big negative.

I would switch to using the exercise mode at Fitbit and not logging it on MFP. I know that MFP added a time for exercise so that Fitbit recognizes when you're adding exercise it registers, but that never worked well for me. I find it much easier to use the exercise mode on mine and just use MFP for food.

Basically, what I did was take my calories burned for a couple of weeks (subtracting any exercise), and averaged that out to get what my daily calories burned is without anything extra. Pretty much, if I had a lazy day, this is about what I would burn. I took my deficit off that, entered it into both MFP and Fitbit, and turned off negative adjustments. This way, if I have a normal day where I don't do a lot, I have what my daily total should be already on MFP. But on days I exercise or do move around more at work or class, I get extra added on.

There is a function to just enter calories burned on MFP, but if you're syncing with the Fitbit, Fitbit might be comparing it to what it has listed and making adjustments to send back to MFP.

StaciMarie1974 wrote: »

Do you have Fitbit synced to MFP? If so, and you're logging it, that is why... It gets info from your Fitbit. So if you log the activity, MFP will not give you credit for the logged activity AND the Fitbit data. Just let the Fitbit do its thing.

This. Fitbit Charge tracks your steps and syncs up to MFP to make calorie adjustments. When you log your exercise into MFP, you are actually double-counting some portion (or all) of the calories that the Fitbit projected you burned, so it takes those away.

I love data and to keep this clean, ALL exercise goes through Fitbit (app or website) and ALL calories goes through MFP. Maybe try to track your exercise only through the Fitbit website to make things simpler.

MsLexii wrote: »

I have a Fitbit (a Charge) and I wear a heart rate monitor every time I exercise. I put my exercise in, and I record how many calories, based off my weight, based off my HRM that I burnt for that exercise session. When I log into MFP it literally subtracts calories away from my work out, telling me that I am NOT burning that much. What the heck? and WHY?

Your Fitbit burn is TDEE (total daily energy expenditure), the calories necessary to maintain your current weight.

Your default MFP calorie goal is activity level minus deficit. Adjustments are the difference between your Fitbit burn and your MFP activity level (sedentary, lightly active, etc.).

If (and only if) you enable negative calorie adjustments in your diary settings, your adjusted goal is TDEE minus deficit.

You can learn more in the Fitbit Users group: http://community.myfitnesspal.com/en/group/1290-fitbit-users

WBB55 wrote: »

If you have a FitBit, I recommend only overriding the steps, etc. it gives you if you're riding a bike or swimming. Anything like aerobics or running, I just let the FitBit do its thing. Sometimes I log exercise if I forgot my FitBit that day... like today...

Ah, yes, there's nothing like getting 1 mile into a run and realizing your Fitbit isn't attached to your sports bra. I always have my GPS watch as a backup now.

editorgrrl wrote: »

Either log your HRM burns in MFP, or see if you can sync your HRM with Fitbit: https://www.fitbit.com/compatibleapps (Or return your Charge and get a Charge HR—it's only US$20 more.)

I second this. I LOVE my Charge HR, it's so handy. Granted, it's not going to be 100% accurate, but it's a lot better than me trying to guess.