Fitbit & weight stablization question from a newbie

decblessings

Hello again! Newbie Melanie here (warning, I'm long winded!). I'm almost 3 weeks into a reset, although the first 3 or 4 days were before I discovered IPOARM and EM2WL and I had just had enough of netting 800-1300 most days and not losing an ounce in two years.

I filled out the spreadsheet to find where my numbers should be. I did try adjusting my height on my fitbit as it said in the spreadsheet, but then it seemed like my RMR was too high, but I may not know exactly what I'm doing. After changing my height for a few days I would look at what it was saying my calorie burn was while I was sleeping and multiply that out to see if that came close to the BMR I've gotten from the calculators (1401) and the spreadsheet (1385). At my actually height, it says I'm burning 13-14 calories per 15 minutes when I'm asleep. I'm figuring that to be a RMR of 1296.

Will it have a big impact on my overall calorie burned estimate if my RMR is potentially under by close to 100? I think I'd rather it mildly underestimate than overestimate when I'm eating at TDEE (which should be somewhere around 2100), but maybe that's the wrong attitude to have.

Also, I'm making my way through NROL and have been reading posts here, but I'm wondering if someone can help me out with a question about weight stabilization during reset.

I've been bouncing around from around 137 pounds to a high weight of 143 for the past two years (I was down to 132 for a minute but that was after a couple very stressful weeks at the first of the year when I was barely eating). I've been weighing daily since this reset began, but actually I have very little emotion about the number. I'm just trying to use it as a tool during the reset. I'll jot down some weigh ins from the past few months...

3/27: 139
5/4:143
5/30: 139
6/30: 137
7/1:139.8
7/3: 138.4 (began reset)
7/6: 140
7/7: 142
7/9: 140
7/11: 137.8
7/16:140
7/18: 139
7/22: 140.4
7/24: 139.6 (approx 26%bf)

There is actually an explanation for that big jump briefly in May which then leveled itself out, but as you can see I'm not really fluxuating any more than I was prior to reset. Any thoughts on what this means?

heybales

Keep in mind night-time calorie burn would be your BMR, which would be 150-250 lower than RMR in reality.
FitBit uses the same value for all non-moving time though, asleep or awake, which isn't correct.

So with correct height, FitBit BMR appears to be about 1296.
Spreadsheet Katch BMR based on BF% is estimated 1385.
Other calc's using Harris or Mifflin BMR are 1401.

So yes, FitBit is underestimating your calorie burn during non-moving times, but not by much, about 90 calories a day, or 3.75 calories per hour. If you have say 12 hrs non-moving time daily, that's only 45 calories, not much to be concerned with.

But the height adjustment could help that be more accurate depending on your non-moving time.

And FitBit is already underestimating many exercise types that you may do, their FAQ points out which ones, non-step based workouts.
If you are giving exactness to weighing your foods and logging everything for the eating side of the equation, why not tweak the tool that handles the burn side of the equation?

If you go through with the height adjustment, you'll want to manually change the stride length, as that will effect your moving time calorie burn estimates. Unless we are only talking a couple inches, may not be worth it then either way.

Also, you should see a monthly fluctuation to weight as your BMR really will change.

decblessings

Thanks Heybales! I will continue adjusting fitbit for a better estimate.

With eating at/near what my TDEE should be for three weeks now and not seeing much of a weight change, is that a good sign or a sign that something still needs adjusted?

Would you expect my weight to fluctuate up or down as my BMR changes with strength training and eating @TDEE?

Sorry, I have a lot of questions as I try to figure this all out. You are so helpful and knowledgeable. It's so nice of you to help so many people achieve health and wellness out of the goodness of your own heart!

heybales

I love troubleshooting, and this is my current kick since I'm doing it too.

Now, next month doing a home project ..... oh wait, I'll be too tired, so maybe not going that direction.

If you had been eating less and not seeing weight or measurement loss for good 3 weeks or more, than the fact not losing anything at higher level doesn't prove anything either. That lower point wasn't potential TDEE, this may not be either.

Good sign not gaining though, means metabolism has gone up.

But slow gain confirms you were at TDEE for whatever the workout is at that point.

Eating a whole 250 more daily than current amount, if truly above TDEE, would cause only a slow 1 lb gain over 2 weeks.
Now that's the test. And since lifting, that gain would not be fat, but LBM, maybe even muscle. So still not a bad gain if it happens.

If it is 1 lb or about, then the previous level was indeed TDEE. If a fast water weight gain, then wasn't at TDEE. If nothing gained, still not at TDEE then.