Please explain deficit, maintenance, and BMR...

Chica650

I've read through the sticky threads and I think I have a somewhat good grasp of all this, but I get so confused when someone says something along the lines of having 1000 calorie deficit, etc. I don't understand what that means...My BMR is the amount of calories my body just naturally burns all day long, right? Like, if I were a sloth and laid in my bed all day, the BMR would be what I would burn. So, if I take in THAT EXACT amount of calories, I'd break even all day, correct? BUT, if I go over that I gain and obviously staying under that I lose...do I have that right?? So, for example, I'm 5 ft. 0 in. tall, weight 162 and my BMR is 1351. I should not eat over 1351 calories if I want to lose weight. SO, MFP puts me on a calorie intake of 1200 calories/day. If I want to be able to eat more than that, I need to exercise and EAT my exercise calories. Then I will see a loss. Do I have that right?

baisleac

Not quite. You're correct in that your BMR is what your body burns if you never get out of bed... but the minute you get up to go pee, you're burning more than your BMR; let alone going to work, cooking dinner, cleaning house, etc. If you eat exactly your BMR, chances are you will lose weight.

You should not eat LESS than your BMR as that is the bare minimum to keep your brain, heart, lungs, and other vital bodily functions going.

edited to add: Please note that BMR calculations are only averages unless you can afford exact testing, and should be reevaluated every 10 lbs or so.

meggonkgonk

Calories Burned From Daily Activity (found on Goals Page)- # of cals you should eat to "break even"
BMR- What you would burn in a coma- supports organ function and such. Usually 300 or more calories less than "Calories Burned From Daily Activity".
Deficit- Calories Burned From Daily Activity-(minus) Daily Calorie Goal

therobinator

if I were a sloth and laid in my bed all day, the BMR would be what I would burn.

Correct.

So, if I take in THAT EXACT amount of calories, I'd break even all day, correct?

Wrong. No one burns only their BMR, because we all get out of bed and go about our lives. If you only ate you BMR, you'd lose weight (slowly) because in reality you are burning more than your BMR.

BUT, if I go over that I gain and obviously staying under that I lose...do I have that right??

No, not right. If you go over what you ACTUALLY burn (BMR + daily normal activity calories), then you will gain weight.

I should not eat over 1351 calories if I want to lose weight.

Incorrect. See above. You should not eay over what you daily recommended calorie intake it, if you want to lose weight.

MFP puts me on a calorie intake of 1200 calories/day. If I want to be able to eat more than that, I need to exercise and EAT my exercise calories. Then I will see a loss. Do I have that right?

This part you have right.

MyFitnessPal sets 1,200 as the absolute minimum that anyone should be eating, to prevent you from going into starvation mode (which takes a long time to happen, but happend if we continually don't feed ourselves enough). MFP set you at the minimum, most likely, because you selected 2+ pounds per week to lose....so 1,200 is the least you can eat. As long as you've given MFP all your accurate data (height/weight) and it tells you to eat 1,200 calories a day (or for someone else 1,455 calories per day), that that's what you eat....if you exercise off 500 calories, you add 500 calories to your intake.....so that your NET calories for the day end up being 1,200 (or 1,455 for someone else).

I hope that makes sense. Feel free to ask more questions, of course.

rileysowner

BMR-Basal Metabolic Rate is the calories your body would burn just to stay alive. If you did nothing all day but lay still in bed you would burn your BMR. Once you move you add calories above that BMR. BMR is an estimate only since everyone is different, but it will be pretty close for most people. The actual calories you burn in a day will be more because you will be getting up and doing things. Theoretically if you ate the number of calories of the BMR you would lose weight because of those calories above you BMR that you burn in your day to day activity.

The calorie deficit is the amount below the estimate of your BMR plus you estimated normal daily activity level. Thus a 1000 calories deficit would be 1000 calories less that what it is estimated you would burn in a normal day excluding exercise. Again, if you eat at you BMR you would lose weight slowly, but since the BMR is an estimate yours could be slightly different that the one calculated by MFP.

Exercise add calories above what you normally burn in a day. Since your deficit is based on what you normally burn in a day, that would mean exercise increases your deficit. That might at first look like a good thing, and if you have a lot of lose it can be, but for those who are not obese too big of a calorie deficit for a long time can result in health issues, slowed down weight loss, temporary weight gain, slowing down your BMR and using your muscles for fuel which will further slow down your metabolism.