Considering the Fitbit calorie adjustment on MFP is NOT just exercise, but the total difference between MFP's estimate of non-exercise daily burn and Fitbit's calculation of daily burn including exercise, sure, very easy.

Question is, how big are the adjustments on rest days?
That will tell you if you selected the right MFP activity level for the non-exercise aspect, if minimal adjustments.

And Fitbit is going to be underestimated in general, for daily burning and exercise.

So look at those numbers, you are likely burning more than 2700, unless you have lost a lot of muscle mass from prior dieting attempts.
You are eating gross 1377.

You think the body is happy getting half what it wants?
You think the body is going to make improvements from exercise that require more energy when it's missing that much already?

The body's response to that kind of stress is slow down daily burn, and risk muscle mass, and add on water from elevated cortisol.

If you want to keep doing the Fitbit sync and adjusting daily eating as needed to match what you burned, you need to pick a reasonable goal amount.

That's a rather very light goal for that height, are you going to be a professional runner where no extra muscle is required?

Because my race weight in my late 20's was 155 with about 5% BF, at 5'10". And that was with slow swimming because of bad shoulders, so not as much muscle upstairs as other triathletes might have. I still had my high school running body basically.

You should be at no more than 250 cal deficit.
You'll likely be shocked at well the workouts become, and how well the body is willing to transform when you don't stress it, but help it recover.

If your average daily TDEE is 2760 (as estimated by Fitbit, which sounds legit--as you are a runner and male), with so little to lose, eat up and trust your Fitbit. A 10% cut (from the 2760) will give you a reasonable ~1/2 lb/week loss.

And, yep, you'll be amazed at how fueling your training at the higher level will lead to great performance gains. No need to stress your body with such aggressively low calorie intakes. Completely unnecessary and possibly detrimental to your health to go so low (fatigue, training injuries, muscle wasting, malnutrition, etc.).

sgorski63 wrote: »

Thanks everyone. I have adjusted MFP to moderately active - giving me over 1400 to start and fitbit still adjusted it upward. I will increase to match fitbit - 15% until I am at 150lbs. Then I will start strength training as well - coincidentally when the new sessions at my gym start in March.

You didn't change your weight loss goal to 250 deficit, or 1/2 lb weekly, did you?

I don't think the math shows that yet.

Make sure you manually log the strength training workouts, as non-HR devices will badly underestimate calorie burn, HR devices will inflate it.