Confused about BMR/MFP's recommendation

rjdunn87

Since I joined the site, I've been using the MFP method of eating at a deficit, logging exercise and then eating back some or all of the exercise calories. However, lately I've been reading up about the TDEE method and wondering whether this might be a better choice for me, though I'm not sure I entirely understand it. I've lost 6.5 pounds in a little over a month, and don't get me wrong, I'm thrilled with that progress. But I want to be smart and do all the research I can about different methods so that if and when my results change or I hit a plateau, I don't freak out.

Anyway, my point is, I decided to calculate my TDEE just out of curiosity. I used MFP's BMR calculator and it says that my BMR should be approximately 1535 calories. However, when I joined MFP and set my goal of 1.5 pounds a week, it gave me a calorie goal of 1360 daily that I've been trying, sort of successfully, to stick to.

So now I'm confused! If your BMR is the minimum calories your body needs to function, why would MFP give me a goal so far below it? Am I harming myself/my metabolism by eating this way? 1360 does feel pretty low, but I've also been losing, albeit slowly, so… I don't know. Sorry for the rambling, I guess I'm just confused. This whole "taking weight loss seriously" thing is new for me and I really want to be sure I'm doing everything as healthily as I possibly can.

rjdunn87

Gentle bump!

refinedredbird

First of all, I love your avatar.

Second, the goals of MFP are based on how much weight you want to lose per week. So if you don't have a lot to lose, but you want to lose 1.5 lbs a week, that's a large deficit and may go below your BMR. I personally prefer to use the TDEE method because I ended up feeling increasingly hungry with MFP's goals for me. Also, if you are setting up your TDEE and include your activity level, then you don't have to worry about logging your exercise or wondering how many calories you really burned.

rjdunn87

Thanks! I have MFP set at 1.5 pounds a week, and I have anywhere from 30-50 pounds to lose. I've never been much smaller than where I am now as an adult, so I'm aiming for that 30 pound goal and then will reevaluate.

rjdunn87

Also, if I were to use the TDEE method I would be eating around 1850-1900 calories a day. I guess this might be a stupid question, but that just seems so high! Is it reasonable to expect I would still lose 1-1.5 pounds a week with that intake?

For reference, I currently weigh 178 and am trying to get to 150. My diary is public if that helps.

rjdunn87

I hate to be an annoying bumper, but was hoping for more input?

southerndream24

Nope, not high at all. I'm 5'3, a size 0, and my calorie goal is about 1900 right now on a cut. I work out about 6 days a week and sometimes twice. TDEE gives your body the amount that it truly needs. I have enough food to fuel my workouts and keep me satisfied. Trust it.

rjdunn87

Nope, not high at all. I'm 5'3, a size 0, and my calorie goal is about 1900 right now on a cut. I work out about 6 days a week and sometimes twice. TDEE gives your body the amount that it truly needs. I have enough food to fuel my workouts and keep me satisfied. Trust it.

Thanks

WalkingAlong

So now I'm confused! If your BMR is the minimum calories your body needs to function, why would MFP give me a goal so far below it? Am I harming myself/my metabolism by eating this way?

Because it's not dangerous to eat below your BMR. It's a myth that it harms your metabolism. Your body meets its caloric needs for all your activities (including your BMR) while in deficit by burning the stored calories in body fat. You can use 1360 or 1860 and lose weight, it's just a trade-off between speed and comfort.

geebusuk

Because it's not dangerous to eat below your BMR. It's a myth that it harms your metabolism. Your body meets its caloric needs for all your activities (including your BMR) while in deficit by burning the stored calories in body fat. You can use 1360 or 1860 and lose weight, it's just a trade-off between speed and comfort.

This.

They are both ways to arrive at a number.
It is the number that is important, not how you get to it.
If you up your calories, your body will have higher energy reserves, so it will burn less from existing reserves.
However, possible that if you burn to much from existing reserves, especially with not that high a proteing intake, you may be burning muscle as well as fat.

wild_wild_life

Also, if I were to use the TDEE method I would be eating around 1850-1900 calories a day. I guess this might be a stupid question, but that just seems so high! Is it reasonable to expect I would still lose 1-1.5 pounds a week with that intake?

For reference, I currently weigh 178 and am trying to get to 150. My diary is public if that helps.

Check out this link, it might help: http://www.myfitnesspal.com/topics/show/819055-setting-your-calorie-and-macro-targets

Since 1 lb is equivalent to around 3500 cals, in order to lose 1 lb a week you would need to be at a 500 cal daily deficit (500x7=3500). To lose 1.5 lbs, you would be at a 750 cal daily deficit. MFP sets your calorie goal before you do any exercise, so to give you your goal, MFP basically took 750 cals off what it calculated to be your maintenance with daily activity. That's why, when you exercise, you are supposed to eat more to keep the same deficit.

For the TDEE method, those calculators give you your estimated maintenance WITH exercise, so in order to lose 1.5 lbs a week with that method, you just subtract 750 from your TDEE. You do not eat extra cals back for exercise because they are already factored in.

As you can see, the MFP and TDEE methods will give you approximately the same goal in the end if your rate of loss is set the same for both of them. With the TDEE method, of course, the exercise cals are averaged over the week so you don't eat more the days you exercise. MFP may be a better choice for people with irregular exercise schedules.

Hope that makes sense.