Changes to definitions and advice

PAV8888

I'm putting this up mainly for discussion and I haven't triple checked the numbers and all that.

Something Ann mentioned in a post about changes to definitions, together with people getting higher goals prompted me to re-check a maintenance setup based on various "activity level" options.

MFP used to be based on Mifflin RMR (sailrabit or search for MFP BMR to see the values). You then multiply the base mifflin estimate by an activity factor that you hope will capture the energy you spend by doing things.

Not very active was an activity factor of 1.25 x BMR and included activity compatible with about 3000 steps per day within the level.

Lightly active was 1.4. Active was 1.6. and very active 1.8

When I punched my numbers in Android today (subject to marginal rounding) I got 1.4 for not very active, 1.6 for lightly active, 1.8 for active and 2.0 for very active.

Based on the old numbers and definition levels I thought that a 20% deficit off TDEE was quite adequate for most people on the balance of speed vs long term stability. With people with adipose levels compatible with bmis in the 30+ range being able to support larger deficits in the 25 to 30% range till the ~bmi 27/28 range, especially during the first six months or maybe even a tad longer.

I don't know how well device integration is working these days. In the past, with device integration functional and negative adjustments enabled, at the end of the day at midnight, devices would fully replace the MFP activity level choice (pre estimate) with their own "evidentiary" TDEE estimate through the exercise adjustment mechanism.

So in one respect nothing changes at all in terms of the definitions and the pre estimates *if one uses a device* and if devices continue to function as expected. By midnight no matter what activity level you choose, your TDEE will get adjusted to whatever it was that your device detected.

But if people are relying only on the MFP definition and then manually adding exercise activity too... 🤷‍♂️

My rule of thumb was that activity in the 16000 step range was the top of an AF of 1.8

So the "tops" were I my mind around: 3500 1.25; 6000 1.4; 10000 1.6; 16000 1.8

I guess the new numbers may make 1000 Cal goals "safer" for lower tdee individuals 🤷‍♂️

Anyway something to keep in mind and it explains the increased eating goal posts from people who lost weight and now get higher goals.

nossmf

Don't have any input on the numbers involved, just wanted to post that I followed your logical argument and did not find any grammatical or logical errors. I have used MFP for 15+ years, always using the "sedentary" setting and adding intentional exercise while ignoring steps taken, and have been satisfied with the results in terms of gaining/losing weight (I've done both during my time here).

Lietchi

My goal went up somewhere between 200 and 250 when I went through the goal setup again. And I need to check again, but a few weeks ago device integration was not working well, the adjustment at the end of the day would give me a few hundred calories too many.

AnnPT77

Thanks for checking that out, PAV . . . sounds like I was remembering correctly. I would've gone back to check, but though I could remember it was in a thread someplace, I had zero memory of the context to be able to search for it.

I can understand why they might want to make a change, but it would have been nice for something of that big an impact if they'd trumpeted about it a little more loudly and diversely. I haven't checked to see if there were any relevant announcements anywhere in update notes or the like.

PAV8888

so... as an example my Mifflin RMR is 1488 as I can verify by using
https://www.myfitnesspal.com/tools/bmr-calculator or by going to
https://www.sailrabbit.com/bmr/ and using my current stats.

Before the changes, MFP's guess in terms of maintenance calories (if I were to select not very active/sedentary as my activity level) used to be BMR * 1.25 = 1,860.

With the new calculation MFP's guess for my TDEE, if I select not very active/sedentary as my activity level, is BMR * 1.4 = 2083. A difference of 223.

That said, I have consistently farmed out my TDEE estimate to Fitbit (and it has been in the 1.8++ range for the past 10 years) and I just navigate based on logged calories vs FITBIT TDEE vs scale level results and assign all observed discrepancies to "Fitbit TDEE error". Because of course my logging could never be wrong!!!!

Based on a couple of "enhanced" AI searches there does seem to exist a "goodly" amount of support for defining 1.4 as not very active / sedentary.

So... all we really have is that the estimates of how much one can eat have gone up from where they used to be pre 2025, and that people should probably log carefully and make decisions by reviewing their actual vs expected weight level changes after sufficient time.

AnnPT77

PAV8888 wrote: »

so... as an example my Mifflin RMR is 1488 as I can verify by using
https://www.myfitnesspal.com/tools/bmr-calculator or by going to
https://www.sailrabbit.com/bmr/ and using my current stats.

Before the changes, MFP's guess in terms of maintenance calories (if I were to select not very active/sedentary as my activity level) used to be BMR * 1.25 = 1,860.

With the new calculation MFP's guess for my TDEE, if I select not very active/sedentary as my activity level, is BMR * 1.4 = 2083. A difference of 223.

That said, I have consistently farmed out my TDEE estimate to Fitbit (and it has been in the 1.8++ range for the past 10 years) and I just navigate based on logged calories vs FITBIT TDEE vs scale level results and assign all observed discrepancies to "Fitbit TDEE error". Because of course my logging could never be wrong!!!!

Based on a couple of "enhanced" AI searches there does seem to exist a "goodly" amount of support for defining 1.4 as not very active / sedentary.

So... all we really have is that the estimates of how much one can eat have gone up from where they used to be pre 2025, and that people should probably log carefully and make decisions by reviewing their actual vs expected weight level changes after sufficient time.

You flaming radical, you.

PAV8888

Ann you got me there 🤷‍♂️

I'm just not sure whether the new numbers will make it easier or harder for people starting out.

I suspect they will confuse people coming back after a while.

Oh well. Unless manual exercise adding has also improved to account for netting out base calories we have further convergence towards 50% of non device accrued exercise Cal especially for long duration lower MET activities.

When configured as sedentary a 3 MET activity should now be estimated closer to 1.6 * BMR minute per minute instead of the previous 1.75 and the nominal 3. And when configured very active it should be estimated at about 1* BMR minute per minute instead of the previous 1.2 and the nominal 3.

So 33% eat back if very active and 53% when sedentary for long duration low intensity activity such as a long walk.

Of course more vigorous would have a higher eat back. Short duration would not matter as much because it would be a small overall value. And device accrued exercise represents a different adjustment than manual exercise adding so it remains essentially 100% eat back when working properly!

Eeeek 🤯🤣

Which is why I'm that type of radical!😎🧐🤔

yirara

I have a custom set of calories, and I use custom entries for various exercises. Works for me, regardless of what happens in the background.

springlering62

I just read that as “Muffin” RMR and was wildly happy for a moment.

Damn. Same as fruit oil. Just one disappointment after another these days.