Fitbit vs MFP

menyeca71

I'm alittle confused.. I just linked the two together, and created a deficit of 500 calories with Fitbit.. Today Fit bit said I ate 1615 calories and burned 1807 calories.. definitely not close to a 500 deficit.. but then I move over to MFP and my net goal is 1200 calories - 1615 calories + 442 for exercise = 27 calories remaining.. I'm done eating for the night.. Why did MFP tell me to eat the extra calories if I clearly did not meet my 500 deficit?
- Hope this makes sense

SillyCat1975

I'm having a crazy issue with mine too. I'm thinking about unlinking them. I know I did my cardio and burned 700 calories, once I linked with fitbit (again) It told me that I had 879 calories burned, HUH? Plus it shows me as 130 Very Active Minutes... I'm like HUH again. Because to me, this is foreign language, I'm thinking of unlinking them again.

macgurlnet

The 1200 calories is WITH a 500 calorie deficit.

So MFP figures your maintenance is around 1700. Subtract 500 to give you 1200. If you burn off 442 with exercise, you need to eat more so you're NETTING 1200.

The math works out fine.

Don't worry about what Fitbit says right now - it calculates your calories burned over 24 hours. You SHOULD see a 500 calorie difference between eaten and burned if you look at today's data tomorrow - after midnight - when Fitbit has finished estimating what you've burned.

MFP doesn't do the calculations the same way which is why things look "funny" between the two sites.

~Lyssa

shadow2soul

Fitbit shows your calorie burn up to the minute. You will still be burning calories between now and midnight. Your BMR for the rest of the night + the calories you burn doing any daily activity for the rest of the night have still not been tracked or added to your burn yet.

This is how my day looks as of right now. See how there is no calorie burn after 8pm, well that's because it hasn't happened yet. Fitbit doesn't add calories until they happen. Where as MFP estimates what your day will be like before it happens.

@lisacarroll18
Fitbit adjustment is the difference between what Fitbit tracked your TDEE to be and what MFP estimated. It includes not only exercise, but any daily activity that exceeds expectations MFP has based on the activity level you selected. Example:

1. Anything past the red line = positive adjustment (added calories)
2. Anything below the blue line = negative adjustment if enabled (subtracted calories or no calories added)

***These aren't random numbers, they are actually mine from a couple days ago. Your's will be different based on your stats, but the way the math works out will still be the same.

As for the active minutes, read about them here:
http://help.fitbit.com/articles/en_US/Help_article/What-are-very-active-minutes/?q=Very+Active+Minutes&l=en_US&fs=Search&pn=1

mittnerk

menyeca71 wrote: »

I'm alittle confused.. I just linked the two together, and created a deficit of 500 calories with Fitbit.. Today Fit bit said I ate 1615 calories and burned 1807 calories.. definitely not close to a 500 deficit.. but then I move over to MFP and my net goal is 1200 calories - 1615 calories + 442 for exercise = 27 calories remaining.. I'm done eating for the night.. Why did MFP tell me to eat the extra calories if I clearly did not meet my 500 deficit?
- Hope this makes sense

Im not sure if this answers because I have no experience with a Fit Bit. However, in MFP if you want a deficit of 500 calories a day you need to start with your Basal Metabolic Rate (BMR). Based on your height and weight MFP will determine the number of calories required to sustain exactly where you are. This is if you literally sat on a couch all day. That is your BMR. Then you tell MFP generally how active you are every day. One of four options from desk jockey to carpenter. It will then add an estimated amount of calories based on the selected option to your BMR. So for me my BMR is ~1800 calories. Im a student so I get little physical activity for most of the day and it adds 500 calories. So including general daily activities MFP says I need 2300 calories to maintain exactly where I am. Now we get to the deficit. If I want to loose albs a week I need to have a deficit of 1000 calories per day (deficit of 500 for 1 lb per week). Thus, MFP will give me a goal of 1300 calories per day.

Now, we see that your "goal" calorie count from MFP includes your deficit. This is why MFP promotes on their pages that if you exercise you can eat additional calories. If your calories eaten always meet your goal calories plus your calories burned then you will always meet your deficit because it is built into the scheme.

I can't be sure exactly how the math in a Fit bit system works but 2 things. 1) the fit bit is probably more accurate when it come to calories burned because it gathers realtime data all day while MFP is based entirely on averages and large assumptions. 2) with out looking too hard because I don't have the info in front of me but the 1807 from fit bit does not include your exercise.

menyeca71

Thank you both for clearing this up for me!! I was so afraid that I had eaten way too much today!