IIFYM vs MFP: 1200 calories

spara0038

Ok, so I'm probably going to open up a giant can of worms here by asking this, but I'm genuinely curious.

I'm 5'2", 130lbs, 25 yrs old, and moderately active. I'm curious how I go about calculating my caloric intake requirement.

So... for IIFYM, if I put in TDEE -20%, I get about 1508cal/day. And, correct me if I'm wrong- that's with not eating any of it back...?

For MFP, if I did 1508 calories - my exercise (usually around 500 calories), I usually get right around 1000 cal/day.

I've heard people SWEAR by not eating under 1200 net, other people who SWEAR by TDEE. Which is it? Because TDEE nets under 1200, is that unhealthy? Or is it fine to eat 1500/day but net 1000?

RHachicho

If your TDEE is really under 1200 then you are probably underweight.

Forty6and2

That's why you eat back the exercise calories. MFP factors in the fact that you want to lose weight and sets you at a deficit at the get-go. Any calories you burn otherwise are extra calories for you to eat more. Keep in mind that you want to lose at a slower weight as you are within a healthy weight range. You should change your goal to lose a half pound per week instead of one pound per week.

spara0038

Forty6and2, I understand what you are saying for MFP, and that makes sense. I'm not really asking about what to set my goal at, but rather to confirm that my understanding that you should not net less than 1200 cal/day using MFP's method is correct.

What I am also trying to understand is how that fits with TDEE. I guess I'm trying to figure out if they follow the same general principle or if you have to essentially choose one or the other. To me, it sounds like MFP requires that you consume more than TDEE.

My TDEE -20%, which I have been told is a reasonable measurement for weight loss, is 1505... meaning that my TDEE is 1886 (what I would need to maintain weight). However, TDEE is based on your level of activity. So, I had to enter into the calculator that I exercise 4-5 days/week to come up with 1886 (and therefore 1505). Some of my activity can work out to 500-1000 calories of activity per day, so consuming 1505 cal/day and potentially burning 1000/day would net 505- which is WAY too low for MFP, but it seems to fit with TDEE..??

Another way to write it:

MFP: 1200 calories (food) -500 calories (exercise)= 700 calories, eat back the calories burned = 1200 net
TDEE: 1505 calories (food) - 500 calories (exercise) = 1050 net (is this too low?)

Forty6and2

You may be calculating too high of a deficit. It looks like you're close to your goal weight, so you should go with a 15% reduction in calories, which will put your calorie level higher. Also, 1886 seems like a terribly low TDEE, are you sure you're using the right calculator?

http://scoobysworkshop.com/calorie-calculator/

This seems to be the one that most people go by. Make sure you log everything correctly on it and it will give you the numbers you need.

spara0038

That's different! I was using the calculator on IIFYM. The one you gave me said TDEE of 2394- a 508 cal difference! And that mathematically makes sense- minus 20% puts me at consuming 1915 cal and then burning the 500 brings me to about a net 1500, which is close to 1200 on MFP.

Thanks!

TeaBea

Ok, so I'm probably going to open up a giant can of worms here by asking this, but I'm genuinely curious.

I'm 5'2", 130lbs, 25 yrs old, and moderately active. I'm curious how I go about calculating my caloric intake requirement.

So... for IIFYM, if I put in TDEE -20%, I get about 1508cal/day. And, correct me if I'm wrong- that's with not eating any of it back...?

For MFP, if I did 1508 calories - my exercise (usually around 500 calories), I usually get right around 1000 cal/day.

I've heard people SWEAR by not eating under 1200 net, other people who SWEAR by TDEE. Which is it? Because TDEE nets under 1200, is that unhealthy? Or is it fine to eat 1500/day but net 1000?

There's TDEE which is all inclusive: BMR (basal metabolic rate) + activity level (ie: sedentary) + exercise.....all together this is TDEE (or maintenance).

You take a percentage off......that percentage depends upon how close you are to goal. 30% off if you are obese......5% if within single digits.

MFP ideally starts out using height, weight, age, gender......but the number get thrown off track when people assume they can lose 2 pounds a week...even if they are close to goal.

TDEE includes exercise.....so you take an appropriate "cut".....and just eat those calories. You don't even need to log exercise. If you took a cut of 20%, but that was lower than your BMR ....then you're doing it wrong.

MFP uses 1200 as it's lowest default.....but with exercise, most women would eat more. Ideally these 2 methods should be fairly close....provided all the setting were the same.