Adjusting MFP calorie goal to work with Garmin device

mtaratoot
mtaratoot Posts: 13,168 Member
in Fitness and Exercise
I hope this is the right category to ask this question. It seems as good as any.

I am looking for your experience with adjusting MFP calorie goals to make a calorie expenditure tracker is more accurate with respect to actual calories expended in a day.

I was recently given a very nice fitness tracker. I'd been thinking about getting a cheap one to track my pulse when I exercise and maybe count steps. Now I have one, and I'm enjoying getting to know how it works and use its features.

It's a Garmin device. It tracks "active" calories differently than MFP. Garmin uses resting metabolic rate (RMR) as a base for caloric expenditure, and it adds ALL activity is "active" calories. That's different from MFP because MFP uses non-exercise energy expenditure (NEET) as a base for caloric expenditure, and only adds calories for intentional exercise.

When I sync my device, it sends MFP an estimate of calories expended. Then MFP adds them to my calorie allowance. This gives me more calories than I actually should eat because my device counts my normal day-to-day activity (non intentional exercise) as part of the active calories. So I've gained a little weight :smile:

I've used Sailrabbit to get a decent estimate of calorie needs, and it tracks pretty close to what I see in MFP and my experience with losing/maintaining/gaining. Sailrabbit gives basal metabolic rate (BMR) and TDEE estimates, but no RMR estimate.

So -- > Two questions:

1. Do you adjust your calorie goal in MFP lower (i.e., closer to RMR than NEET) so that your device is a more accurate representation of your day? If so, what do you use as an estimate of RMR?

2. Have you found your device to be relatively accurate with respect to calorie expenditure? In other words, if you obey what it tells you, so you get the results (weight loss/maintenance/weight gain) that you are striving for?

Thanks!

Replies

  • karenvandam
    karenvandam Posts: 23 Member
    I also have a Garmin to track exercise calories. On MyFitnessPal, I set my activity level at sedentary. I also allow for negative calorie adjustments in case I have a really sluggish day (sitting on an airplane for 12 hours for example). By doing this, I feel like the calorie adjustment from Garmin comes pretty close to reality. On days where I walk a lot at work, it gives me approximately enough extra calories to match what MyFitnessPal would give me if I set my level to moderate activity. When I actually eat to my calorie goal, I seem to lose weight the way I would expect.
  • cheryldumais
    cheryldumais Posts: 1,907 Member
    karenvandam wrote: »
    I also have a Garmin to track exercise calories. On MyFitnessPal, I set my activity level at sedentary. I also allow for negative calorie adjustments in case I have a really sluggish day (sitting on an airplane for 12 hours for example). By doing this, I feel like the calorie adjustment from Garmin comes pretty close to reality. On days where I walk a lot at work, it gives me approximately enough extra calories to match what MyFitnessPal would give me if I set my level to moderate activity. When I actually eat to my calorie goal, I seem to lose weight the way I would expect.

    Mine is exactly the same. I’m using a Garmin Vivofit2.

  • AnnPT77
    AnnPT77 Posts: 32,034 Member
    edited December 2018
    My Garmin Vivoactive 3 significantly underestimates my daily calorie burn, as I estimate it based on data from a year of weight loss and 3 years of maintenence. Therefore, I don't sync it to MFP, so can't answer the questions about syncing.

    FWIW, it seems to be off by roughly the same amount as many online calculators, so if those are close for you, perhaps your Garmin will be close, too.

    The tracker devices are still just estimating, and those estimates still draw from about the same body of research. They can fine tune the final estimate by using data about your body movements and possibly heart rate, if the device measures the latter.

    It's a more personalized estimate, but it's still an estimate. Surprisingly many people don't realize that.
  • Duck_Puddle
    Duck_Puddle Posts: 3,224 Member
    Garmin calculates total calories burned (TDEE) and sends that number to MFP. Mfp then subtracts the number of calories fhat it thinks you’ve burned (NEAT plus whatever workouts are showing in MFP). The difference is then added to your diary as a Garmin “steps” adjustment (that has nothing to do with steps).

    Both systems are factoring in TDEE numbers in this.

    Garmin active calories is what it adds to your resting-to total your TDEE. Active calories may or may not be sort of close to your total exercise calories/adjustment, but maybe not because they aren’t used.

    Mfp is using your NEAT plus your workouts (which should also equal your TDEE). NEAT should include all non exercise activity. So ALL your activity should still be counted-if you run around after toddlers all day, that’s activity (although maybe not “exercise”).

    As you’ve pointed out-they are using slightly different mechanisms to arrive at the same destination (TDEE). And the TDEE is all that’s used in calculating the adjustment amount.

    So the end calculation is TDEE-TDEE. The rest doesn’t matter because none of those figures are used outside their individual systems.

    It’s possible your Garmin is overestimating your total calories burned. As @AnnPT77 says, it’s an estimate which is reasonably close for a lot of people, and horribly off for those who are probably also horribly off by other calculations.

    It’s also possible that your logging is not as tight as it could be and now that Garmin is adding more calories for more activity, you’re gaining. This might be projection on my part.

    Anyway-to answer your questions.

    1. Because it’s TDEE to TDEE no adjustment is necessary for RMR/BMr/NEAT etc because none of those are factored into the comparison between systems. So no. I don’t adjust anything.

    2. I’ve used a bunch of trackers. Some read a little high, some read a little low, most are reasonably close (close enough that I lose/gain as expected when I leave things alone and eat all my exercise calories). That tends to veer off course when my logging gets a little loose and I weigh fewer and fewer things and “forget” things here and there.


  • heybales
    heybales Posts: 18,842 Member
    As above - no need to fiddle with the numbers, but if you want to possibly improve things so you don't have to think about how far off it might be, there are a few things.

    Getting stride length down - if you have a lot of daily steps, exercise or not - the stride length matters more.

    Because steps = distance with time and weight = calories.

    So walk a known track distance (1/2 mile or more) at avg daily pace (not grocery store shuffle, not exercise pace) which 2mph might be right about there, and confirm the distance is right.

    Garmin Connect has nice method for inputting what you find and it calculates stride length to base it's dynamic calculations on with each step.

    That could improve Garmin's estimated daily burn.

    With no HR involved, that's not going to confuse the normal daily activity burn as some people have issues with (device thinks you are in exercise mode and switches to HR-based calorie burn which is inflated for what is being done) - but your purposeful exercise calories will be incorrect for non-step-based workouts - swimming & weight lifting obviously, stairmaster, elliptical, biking, ect.
    Garmin's database calculation on some of those is rather out there too as I recall, I think Strength training was overboard, not much else I've manually entered without my own calories to use. So careful there.

    Ditto's to Garmin's side being a tad confusing - especially since their figures for Active non-exercise calories changes. I basically ignored their side except to confirm they counted the exercise in with what they sent to MFP.
    My MFP account has issues, and an update after exercise is added sometimes won't come across.
  • mbaker566
    mbaker566 Posts: 11,233 Member
    i have them linked and eat what mfp tells me to
  • lanerhys87
    lanerhys87 Posts: 1 Member
    Old thread, but thought I'd add my two pennies worth in case it helps anyone.

    The previous commenters seem to understand the methodology better than me, but a simple way I've found that works for me:

    - Find out your BMR
    - If you want to maintain, then set your MFP daily calorie goal to your BMR and set your lifestyle to sedentary so it doesn't mess with it. MFP then syncs with Garmin & adds and those active calories to your total daily goal, making it dynamic.
    - if you want to lose 1lb per week then do the same as above but minus 500 calories from your dail goal you set in MFP (adding up to the 3,500 needed over a week). E.g. Your BMR is 2000 so you set your daily goal to 1,500. Your Garmin then says you burned 500 calories by the end of the day which means you could eat 2000 calories and still be on track to lose 1lb

    I've found that it is surprisingly accurate doing it this way because Garmin's calculation for working out active calories is one of the most accurate out there. Keep an eye on the results and you can adjust your goals as needed. E.g if you've been aiming for 1lb loss a week but consistently only lose 0.5lb then you need to take more calories off your goal.
    The only downside to this is that you need to work out your BMR as you lose weight and update your daily goal as needed, because it'll obviously go down as you lose. I updated by BMR after every few lb lost to keep it up to date.
  • heybales
    heybales Posts: 18,842 Member
    lanerhys87 wrote: »
    Old thread, but thought I'd add my two pennies worth in case it helps anyone.

    The previous commenters seem to understand the methodology better than me, but a simple way I've found that works for me:

    - Find out your BMR
    - If you want to maintain, then set your MFP daily calorie goal to your BMR and set your lifestyle to sedentary so it doesn't mess with it. MFP then syncs with Garmin & adds and those active calories to your total daily goal, making it dynamic.
    - if you want to lose 1lb per week then do the same as above but minus 500 calories from your dail goal you set in MFP (adding up to the 3,500 needed over a week). E.g. Your BMR is 2000 so you set your daily goal to 1,500. Your Garmin then says you burned 500 calories by the end of the day which means you could eat 2000 calories and still be on track to lose 1lb

    I've found that it is surprisingly accurate doing it this way because Garmin's calculation for working out active calories is one of the most accurate out there. Keep an eye on the results and you can adjust your goals as needed. E.g if you've been aiming for 1lb loss a week but consistently only lose 0.5lb then you need to take more calories off your goal.
    The only downside to this is that you need to work out your BMR as you lose weight and update your daily goal as needed, because it'll obviously go down as you lose. I updated by BMR after every few lb lost to keep it up to date.

    It's either changed or you have misunderstanding on how it works.

    Garmin doesn't send Active calories that it shows on it's site to MFP.

    Garmin like Fitbit and few others, sends a correct Daily Burn (or TDEE) to MFP to do math with, and MFP then corrects itself.

    So the suggested method may work for you, but that setting a default eating goal @ BMR is way off. Unless you are using terms incorrectly and don't mean BMR.

    Just selected the correct weight loss rate for amount to lose - say 500 for 1lb weekly.
    It really doesn't matter what MFP estimates you'll burn - it's going to get corrected.

    Garmin sends the TDEE over say near end of day and MFP estimates it'll end up at 2000.
    If MFP already estimated you'd burn 2000 set to sedentary (or lightly-Active or anything, doesn't matter) - then no adjustment.

    Base eating goal 1500 still.

    If Garmin sent what would end up at say 2500 because of being very active that day, then there will be a 500 adjustment.

    Base eating goal 2000 now, still 500 deficit.

    If Garmin sent same figure to end at 2500, and a workout of 500, then:
    2500 - 2000 MFP - 500 workout = 0 adjustment

    base eating 1500 + 0 + 500 workout = 2000 eating goal, still 500 deficit.

    If Garmin sent figure to end at 2250 because you were less than sedentary after a workout, and a workout of 500:
    2250 - 2000 - 500 = neg 250

    Eating 1500 - 250 adj + 500 workout = 1750 eating goal, still 500 deficit.

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