BMR vs. Measured RMR via Exhaled Air Analysis
DittoDan
Posts: 1,850 Member
So, while I was studying Bariatrics, the Hospital I signed up with was: Henry Ford Hospital (HFH). (I have since cancelled). While reading their voluminous paper work I came across a test they do for their Weight Loss Center called: Metabolic Testing/Exhaled Air Analysis
Basically they measure how much Carbon dioxide you exhale and determines what your measured BMR is. BMR (Base Metabolic rate) is the amount of calories your body expends at rest (no movement at all). It is also called RMR (Resting Metabolic Rate).
So, I wanted to do this test, (the science side of me wanted it), I called my insurance and they covered it, I e-mailed my endocrinologist and he sent me an Rx. Today, I did the test.
The test is fairly easy. You have to have fasted for 5 hrs. You go into a small room, they have you sit in a chair, you have to sit still for ten minutes, no cell phone, they turn off the lights and they suggest you don't think of things that would upset you.
They come back in and put a "nose clamp" on your nose to prevent you from breathing through you nose. Then a simple hose/mouthpiece and you breathe through the tube (that is hooked up to a small machine (ReeVue)). The mouthpiece has a one-way valve that makes all the air you exhale, pass through the machine. They turn out the lights and breathe into the machine for 10 minutes.
At the end of the test, the machine reported that my BMR was: 1872
So, to compare, I went to the popular BMR calculator website:
Keto Calculator http://keto-calculator.ankerl.com/
I wanted to compare HFH to the Keto Calculator. I put in my info and the Keto calculator gave me these numbers:
1,943 is pretty close. If you take the difference, multiply it by 365 days = 25,915 calories @ year. Divide that by 3,500 (calories in a pound) = 7.4 pounds.
In my report from HFH, for a sedentary person, they calculate my TDEE (Total Daily Energy Expenditure) at 2,246. They arrive at this calculation by taking the RMR X 1.2 (sedentary).
So according to HFH if I eat 2,246 calories a day, I will neither gain nor lose weight (Maintenance).
So I went back to the Keto Calculator and filled out the rest of the info to see what it says for Maintenance to compare with HFH. I went to a link on their site to calculate body fat:
http://www.nowloss.com/online-body-fat-percentage-calculator.htm
I filled it out:
And finished out the Keto Calculator. Doing the math, the difference between HFH & the Keto Calculator amounted to 9 lbs. @ year. In other words, according to Keto Calculator I was "more active" than the actual measured amount from HFH. The test did confirm my belief that am "more" sedentary than the standard calculators. I always tell people I was in the pod next to Neo in the Matrix. LOL! If you don't believe me, see pic:
Dan the Man from Michigan
Blog #13 DittoDan's Milestone's, First's And Good Changes Since Starting the Ketogenic Diet
My Blog: its Ketogenic or Bariatric (How I found the Ketogenic Diet)
Keto Abbreviations, Acronyms & Terminology Used in LCD & Keto Discussion Groups
Basically they measure how much Carbon dioxide you exhale and determines what your measured BMR is. BMR (Base Metabolic rate) is the amount of calories your body expends at rest (no movement at all). It is also called RMR (Resting Metabolic Rate).
So, I wanted to do this test, (the science side of me wanted it), I called my insurance and they covered it, I e-mailed my endocrinologist and he sent me an Rx. Today, I did the test.
The test is fairly easy. You have to have fasted for 5 hrs. You go into a small room, they have you sit in a chair, you have to sit still for ten minutes, no cell phone, they turn off the lights and they suggest you don't think of things that would upset you.
They come back in and put a "nose clamp" on your nose to prevent you from breathing through you nose. Then a simple hose/mouthpiece and you breathe through the tube (that is hooked up to a small machine (ReeVue)). The mouthpiece has a one-way valve that makes all the air you exhale, pass through the machine. They turn out the lights and breathe into the machine for 10 minutes.
At the end of the test, the machine reported that my BMR was: 1872
So, to compare, I went to the popular BMR calculator website:
Keto Calculator http://keto-calculator.ankerl.com/
I wanted to compare HFH to the Keto Calculator. I put in my info and the Keto calculator gave me these numbers:
1,943 is pretty close. If you take the difference, multiply it by 365 days = 25,915 calories @ year. Divide that by 3,500 (calories in a pound) = 7.4 pounds.
In my report from HFH, for a sedentary person, they calculate my TDEE (Total Daily Energy Expenditure) at 2,246. They arrive at this calculation by taking the RMR X 1.2 (sedentary).
So according to HFH if I eat 2,246 calories a day, I will neither gain nor lose weight (Maintenance).
So I went back to the Keto Calculator and filled out the rest of the info to see what it says for Maintenance to compare with HFH. I went to a link on their site to calculate body fat:
http://www.nowloss.com/online-body-fat-percentage-calculator.htm
I filled it out:
And finished out the Keto Calculator. Doing the math, the difference between HFH & the Keto Calculator amounted to 9 lbs. @ year. In other words, according to Keto Calculator I was "more active" than the actual measured amount from HFH. The test did confirm my belief that am "more" sedentary than the standard calculators. I always tell people I was in the pod next to Neo in the Matrix. LOL! If you don't believe me, see pic:
Dan the Man from Michigan
Blog #13 DittoDan's Milestone's, First's And Good Changes Since Starting the Ketogenic Diet
My Blog: its Ketogenic or Bariatric (How I found the Ketogenic Diet)
Keto Abbreviations, Acronyms & Terminology Used in LCD & Keto Discussion Groups
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Replies
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That's so cool that you could get that done and have the cost covered. Very interesting, and you are so good with figuring it all out. Way to go !0
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I had mine done a year and a half ago. It measured me a 1768. I have no idea what to do with that number, since I don't seem to be losing on 1360.0
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@DittoDan
>They turn out the lights and breathe into the machine for 10 minutes.
A 24h session in a metabolic chamber would give you the real numbers. Peter Attia in an interview described his experience, and like you found that the calculators didn't match up.
I think every one should use at least one activity level lower than they think. I weight train but use the Sedentary modifier, and am getting good results.
@IamUndrCnstruction
> It measured me a 1768. I have no idea what to do with that number, since I don't seem to be losing on 1360.
Go lower on the activity multiplier and endeavor to measure more accurately. What are your stats?0 -
I am 211, 5'10" set at sedentary as I have a desk job. I work out 1 to 1 and a half hours a day 4-5 days a week, cardio and lifting. I weigh my food. I try and stay under 20g carbs per day total, but sometimes go as high as 30g total 20g net. I am also on steroids (prednisone) and a host of other meds, and am coming from a vlcd background if any of that makes a difference.0
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Oh...I will say that visually I am getting smaller. I, of course, only measured my waist, which has lost two inches, but I seem to be losing from odd places like my rib cage and lower thighs and arms.0
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Prednisone is evil stuff. You feel like a superhero for a few days and then you start eating like one. Perhaps evil is too harsh of a word since they put you on it to address something worse than those sideffects. I will say that I went on it a few years ago and swore I would never do it again if given a choice.0
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I say the pred is a double edged sword, it works well at what it does, in my case it keeps my lungs from acting up too badly, but it is also a vile substance which wreaks havoc on the rest of your body. I have been on it for three years straight. I am going to talk to my Dr about lowering the dosage.0
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