BMR Confusion?

sarahgreensandthings

So MFP says my BMR is 1730, so I've had my goal set at 1700, but going over frequently and thusly gaining weight. I checked a few more sites (seemed pretty reputable), and they all said under 1700? One as low as 1500? And my FitBit has it waaayyy up at 2400 and I don't know how to change it.
I'm keeping it low (1600) just to be safe, but don't know what I'll so once I get to maintenance. Hopefully my body comp will be more muscle, raising my BMR even though I'm lighter. But I'll cross that bridge when I get there
Anyone else have similar confusion? Should I just consult my doctor once I get to maintenance for the most accuracy?

TavistockToad

are you confusing BMR with TDEE? What are your stats?

StaciMarie1974

Perhaps you don't understand what BMR is?

ninerbuff

sarahgreensandthings wrote: »

So MFP says my BMR is 1730, so I've had my goal set at 1700, but going over frequently and thusly gaining weight. I checked a few more sites (seemed pretty reputable), and they all said under 1700? One as low as 1500? And my FitBit has it waaayyy up at 2400 and I don't know how to change it.
I'm keeping it low (1600) just to be safe, but don't know what I'll so once I get to maintenance. Hopefully my body comp will be more muscle, raising my BMR even though I'm lighter. But I'll cross that bridge when I get there
Anyone else have similar confusion? Should I just consult my doctor once I get to maintenance for the most accuracy?

What's your height, weight and age?


A.C.E. Certified Personal and Group Fitness Trainer
IDEA Fitness member
Kickboxing Certified Instructor
Been in fitness for 30 years and have studied kinesiology and nutrition

sarahgreensandthings

I know that BMR is how many calories my body burns in a day without any effort. And MFP and FitBit have very different readings of what that BMR is, confusing me as to how much I naturally burn and how to eat at a deficit. According to FitBit, I can eat 2,000 calories a day and lose weight, and according to MFP, I'll gain weight. And these sites (all about BMR) read as low 1500, meaning I would have to take in under 1500 calories a day to lose weight. So I'm getting readings all over the board and don't know what to trust. I've been on MFP for two years and have never been this confused.

StaciMarie1974

BMR is the calories your body burns to keep you alive. Its energy spent by bodily organs/systems such as for food digestion, managing body temperature, heart & lung & brain functions.

You also burn calories for 'activity' by moving. If you burn BMR just sitting in a chair all day, consider that some additional energy is used to physically move your body in your normal routines. Odds & ends around the house, movement on your job, hobbies. Its a function of your BMR.

Your MFP goal in terms of calories to eat estimates those 2 numbers and totals them based on your stats & your stated activity level. And then uses your weight loss goal. Such as if your stats/activity level compute that you burn 2000 in a day, and you want to lose 1 pound per week, MFP will tell you to eat 1500.

Then you also burn some extra for intentional, extended cardio exercise. Due to moving multiple major muscle groups for a period of time. THis is NOT considered in your daily MFP goal but be careful not to add in too many extra because it is easy to overestimate exercise calories.

Your Fitbit estimates calories burned from all 3 sources and syncs to send that information to MFP. If Fitbit shows you are burning 2400 in day, 1700 is perhaps a good intake calorie level for you. That would be a deficit of about 700/day.

StaciMarie1974

If you are eating at 1700 and gaining weight, then my first question is: how accurately do you log calories in? And also what is your height/weight? How much weight have you gained and over what period of time?

Gaining weight by eating 1700 could mean you are fairly petite and have a low maintenance level, or it could mean you're eating more than 1700 due to inaccurate or inconsistent logging.

sarahgreensandthings

StaciMarie1974 wrote: »

BMR is the calories your body burns to keep you alive. Its energy spent by bodily organs/systems such as for food digestion, managing body temperature, heart & lung & brain functions.

You also burn calories for 'activity' by moving. If you burn BMR just sitting in a chair all day, consider that some additional energy is used to physically move your body in your normal routines. Odds & ends around the house, movement on your job, hobbies. Its a function of your BMR.

Your MFP goal in terms of calories to eat estimates those 2 numbers and totals them based on your stats & your stated activity level. And then uses your weight loss goal. Such as if your stats/activity level compute that you burn 2000 in a day, and you want to lose 1 pound per week, MFP will tell you to eat 1500.

Then you also burn some extra for intentional, extended cardio exercise. Due to moving multiple major muscle groups for a period of time. THis is NOT considered in your daily MFP goal but be careful not to add in too many extra because it is easy to overestimate exercise calories.

Your Fitbit estimates calories burned from all 3 sources and syncs to send that information to MFP. If Fitbit shows you are burning 2400 in day, 1700 is perhaps a good intake calorie level for you. That would be a deficit of about 700/day.

Okay, that is super helpful! It makes a lot more sense now. Thanks, Staci!

VintageFeline

You don't take your deficit from BMR, it comes from TDEE. How much have you gained over what time period?

TavistockToad

sarahgreensandthings wrote: »

I know that BMR is how many calories my body burns in a day without any effort. And MFP and FitBit have very different readings of what that BMR is, confusing me as to how much I naturally burn and how to eat at a deficit. According to FitBit, I can eat 2,000 calories a day and lose weight, and according to MFP, I'll gain weight. And these sites (all about BMR) read as low 1500, meaning I would have to take in under 1500 calories a day to lose weight. So I'm getting readings all over the board and don't know what to trust. I've been on MFP for two years and have never been this confused.

have you lost weight in those 2 years eating MFPs calories?

cwolfman13

sarahgreensandthings wrote: »

I know that BMR is how many calories my body burns in a day without any effort. And MFP and FitBit have very different readings of what that BMR is, confusing me as to how much I naturally burn and how to eat at a deficit. According to FitBit, I can eat 2,000 calories a day and lose weight, and according to MFP, I'll gain weight. And these sites (all about BMR) read as low 1500, meaning I would have to take in under 1500 calories a day to lose weight. So I'm getting readings all over the board and don't know what to trust. I've been on MFP for two years and have never been this confused.

You eat a deficit of your TDEE, not your BMR...your BMR is merely the calories you burn existing...

For example, my BMR is around 1800...my TDEE (Total Daily Energy Expenditure) is around 3,000 (this includes my exercise)...I lose about 1 Lb per week consuming 2500 calories...that's my deficit.

Mycophilia

You don't gain weight by eating more calories than your BMR. You gain weight when you eat more than your Total Daily Energy Expenditure, which is the sum of your:

• Basal Metabolic Rate (What your body requires for survival)
• Thermic Effect of Food (The energy needed to digest food)
• Thermic Effect of Exercise (Energy spent during exercse)
• Non-Exercise Activity Thermogenesis (Energy spent during daily activity)

StaciMarie1974

Looking at your food log, accuracy I think is the issue.

You logged yesterday evening .5 medium avocado for 117 calories twice. What you consider a medium avocado may not match what this food entry was based on. Weigh your avocado - it has 45 calories per ounce. So for 117 cals it should be 2.6 ounces. Your 1/2 'medium' avocado could have easily been 3, 4 or more ounces. That is not something you can tell by eyeballing it.

1 Bread slice 110 cals. Even if this is what the label says, it also indicates how many grams are in a standard slice. They can easily be 10-20% off and still be ok by USDA guidelines. So if it was supposed to be 45grams and was actually 50, that is more calories.

Peanut butter by tablespoon is another danger area. Go by scale weight. Measuring cups/spoons are not meant for solid food, so you could have another 50, 100 or more calories consumed here than you thought.

These are some examples based on one day.

StaciMarie1974

Using me as an example. I am 42 years, female, 138 pounds at the moment, 5'5.5". Lost weight, was in maintenance, and slowly put on ~12 pounds in 2016. Now working to get rid of it. My BMR is about 1295 per day.

I use a Fitbit One. According to it, based on my daily activity AND my exercise (which is all step based - if you do non-step based exercise, log it - but otherwise just let Fitbit do its thing) I burn a TOTAL of about 1750-1850 per day. This includes energy burn from all sources, so about 355-455 beyond my BMR.

If I eat under 1750-1850 I will lose weight because I'm eating less than I'm using. If I consistently eat at 1300 I will lose faster than if I consistently eat at 1500 or 1700. (It is worth noting that as you lose, your BMR goes down and thus your total daily burn. Its a gradual adjustment not totally relevant for me needing to lose another 10, but if you had 100 to lose the change would be more significant.)

If you are burning 2400 in day, and MFP tells you to eat 1700: eating 1700 should lose weight over time. Results may not show on the scale immediately due to fluctuating water weight. Eating more than 1700 and less than 2400 should still lose weight, but slower. If you're eating 1700 and burning 2400 and NOT losing weight then there is an error somewhere. Either you're not really eating 1700, you're not really burning 2400, there is something wrong medically such as with your thyroid as it impacts the rate at which your body burns calories. The other possibility is you are judging by a very short period of time and water weight is impacting your results.