My numbers on MFP vs. calculated TDEE

JediMasterNaw

I've been on here for 75+ days now and I've been doing well (over 22lbs down!) and, even though I've been managing it, I've been feeling a bit too restricted with my calories set at 1520 with a goal of 2lb/week. So i've been looking in to changing things up a bit with a less aggressive goal. To that end, I was reading an old post that explains BMR and TDEE and used the calculator that post recommended (http://www.fat2fittools.com/tools/bmr/).

However, the calculator on there gave me WILDLY different numbers than MFP does.
My stats:
Current weight: 257.8
eventual Goal weight: 150
height: 5'8"
age: 24
body fat percentage (according to that site's calculator): 55.8%

MFP gives me 1710 calories for 1.5lb/week and sedentary
The TDEE calculator says either 1984 or 1489 for BMR (Which is it??) and TDEE says 2381 sedentary. Taking 20% off of that would be 1905.

I know that the 1710 will work for losing weight and it's easisest to just use MFP's numbers.
I guess my question is...am I doing something wrong with the TDEE calculator? Or am I misunderstanding how that works?

Thanks!

cwolfman13

JediMasterNaw wrote: »

I've been on here for 75+ days now and I've been doing well (over 22lbs down!) and, even though I've been managing it, I've been feeling a bit too restricted with my calories set at 1520 with a goal of 2lb/week. So i've been looking in to changing things up a bit with a less aggressive goal. To that end, I was reading an old post that explains BMR and TDEE and used the calculator that post recommended (http://www.fat2fittools.com/tools/bmr/).

However, the calculator on there gave me WILDLY different numbers than MFP does.
My stats:
Current weight: 257.8
eventual Goal weight: 150
height: 5'8"
age: 24
body fat percentage (according to that site's calculator): 55.8%

MFP gives me 1710 calories for 1.5lb/week and sedentary
The TDEE calculator says either 1984 or 1489 for BMR (Which is it??) and TDEE says 2381 sedentary. Taking 20% off of that would be 1905.

I know that the 1710 will work for losing weight and it's easisest to just use MFP's numbers.
I guess my question is...am I doing something wrong with the TDEE calculator? Or am I misunderstanding how that works?

Thanks!

for one thing, your 20% TDEE cut is a bit shy of a 500 calorie deficit...which would be around 1 Lb per week. so essentially you're comparing a 1.5 rate of loss to a 1 Lb rate of loss...that's a difference of about 250 calories. If you add 250 calories to 1710 = 1,960 calories...a difference of a mere 55 calories. Basically 6 of 1.

Why are you putting sedentary as your TDEE? Are you really?

my guess is that there are two formulas for BMR...one is likely taking your total body weight (less accurate) and the other is only taking into account your lean mass (most accurate). 1489 sounds about right considering I'm a male and my BMR isn't even 1900 calories.

DemoraFairy

I seem to have gotten different numbers to you using the data you provided. Firstly, I can't find a reference to 1489 for your BMR anywhere (though I've got that it says 1984). For the rest, I've got:
Sedentary: 1818
Lightly Active: 2083
Moderately Active: 2348
Very Active: 2613
Extremely Active: 2879

Edit: Just read the page again and it says those numbers are what you should eat to reach your goal, not your maintenance numbers (so those numbers aren't your TDEE for each activity level). So that method recons 1818 for sedentary, MFP recons 1710, which aren't miles apart.

TimothyFish

I don't see much of a problem here. If you subtract 750calories (1.5lbs per week) from 2381, you get 1631. That is slightly lower than what MFP is giving you, but not by much.

JediMasterNaw

Ok, so I was comparing them incorrectly! The 1.5lbs per week is more than the 20% so the number is lower. Thanks!

@DemoraFairy I think the reason we got different numbers is that the post said to put in current weight as goal weight also in order to get TDEE. Sorry, I forgot to mention that part!