What is the most precise way of measuring calorie expenditure?

[blorge]

I'm not talking about internet calculators by the way, was wondering if anyone has had their calorie expenditure professionally measured (if this is even possible) by a nutritionist, specialist equipment or whatever / whoever else would be used to obtain this data?

[AlwaysTryin]

Metabolic chamber

[trance__dreamer]

happy halloween!

[SOJA]

Bod Pod.

[NaLLa8705]

Bod Pod.

Thought those did body fat %?

[SOJA]

Thought those did body fat %?

You know, I'm not honestly sure but I remember someone posted their sheet for proof a few months ago, and it had a BMR on there, I believe. That alone should give some insight to the person who took the test.

[SumDumGoi]

Bod pod measures body fat percentage. Then based on calculations from your lean body mass it will estimate what your BMR is as well. However, BMR only gives you one component of total energy expenditure. Total energy expenditure is the sum of 1) BMR, 2) physical activity & 3) thermic effect of food.

Outside of living inside a whole body calorimeter, the best way to measure BMR would be to have it measured using indirect calorimetry using a metabolic cart. Essentially the metabolic cart measure how much oxygen you consume at rest which then can be used to calculate your resting energy expenditure.



To measure energy expenditure during physical activity is a little more tricky. Obviously your physical activity level will change throughout the day so outside of living in a metabolic chamber or keeping track of every activity you do for every minute of the day the best way to measure this component would be to use an accelermoter such as an Actical. These devices are fancier, more advanced versions of a podometer. They keep track of your movement in the 3 planes (how fast you are moving and how much) and use it to calculate your energy expenditure due to physical activity.

The last component is the thermic effect of food. It is going to take some energy to digest the food you eat. To calculate this you could either have you RMR measured again after every meal (impractical) or you could estimate it based on the number of Calories you eat. Approximately 10% of the total Calories we eat are used for digestion, so you would have to count up all of your Calories and multiply your total Calories by 10%.

Once you know all 3 components you need to add them all together and you will have your total Caloric expenditure. Obviously you can't do this on your own and that is why we use formulas to predict these variables. However if you would like to have this measured start researching local Universities in the Departments of Kinesiology, Health Science and Nutrition. A lot of Universities often have these tools and are sometimes looking for subjects for their studies. Others may have these tools and may be willing to perform these tests for a fee.

[AdamWW]

Darts + Dartboard

[gpoitras]

You know, I'm not honestly sure but I remember someone posted their sheet for proof a few months ago, and it had a BMR on there, I believe. That alone should give some insight to the person who took the test.

RMR? I took one of these earlier this year. The results were as accurate as using the Katch McArdle method of calculating your BMR.

[SumDumGoi]

That is because it uses those formulas to estimate your RMR.

[AlwaysTryin]

Darts + Dartboard

Very true

[avaela]

[(Age x 0.2017) - (Weight x 0.09036) + (Heart Rate x 0.6309) - 55.0969] x Time / 4.184

[blorge]

Thanks for the reply guys.

It seems it requires some serious equipment, so i'll guess i'll stick to the 90% (or so) accuracy of internet calorie expenditure calculators for now

[gpoitras]

That is because it uses those formulas to estimate your RMR.

Can you explain how the RMR test uses the same formula? The RMR I took measured gas exchange.

[gpoitras]

Thanks for the reply guys.

It seems it requires some serious equipment, so i'll guess i'll stick to the 90% (or so) accuracy of internet calorie expenditure calculators for now

I think I paid $180 for both RMR and VO2 Max tests while in Los Angeles. Not sure what just a RMR runs. Sometimes universities will offer them, otherwise google your area.

[GavriloPrincip]

How accurate is the Bodymedia Fit/Bodybugg?

[SumDumGoi]

Can you explain how the RMR test uses the same formula? The RMR I took measured gas exchange.

Are you talking about having RMR measured using the Bod Pod? The Bod Pod itself doesn't measure gas exchange. It relies on the the relationship between pressure and volume to determine how much air you displace when sitting inside of the chamber (P1 x V1 = P2 x V2). The front chamber you are sitting in contains a known volume of air. Then it measures the change of pressure between the front and rear chamber (the rear chamber is hidden from view) and uses this relationship to calculate volume of displaced air. Once you have volume you can calculate your body density (density = mass/Volume) and once you know your density you can calculate body fat percentage.

You might have been asked to blow 3 times into a hose while sitting in the Bod Pod. This test does not measure gas exchange, but rather is a way of calculating your lung volumes. The more air that is in your lungs the more air will be displaced from the front to the rear chamber which would artificially decrease your body density and result in an increase in body fat percentage. However, if you were not asked to blow into the tube ( a lot of times people don't do this) the machine will estimate what these volumes are based on height, weight, age and gender.

It is easy to think that the Bod Pod is measuring gas exchange, as you are sitting in an air tight chamber, but it is not measuring the amount of oxygen you are consuming. It is only measuring the volume of air your displaced from the front to the rear chamber during the test. Once you know what your body density is the machine uses a formula to calculate your RMR based from your lean body mass.

[SumDumGoi]

I think I paid $180 for both RMR and VO2 Max tests while in Los Angeles. Not sure what just a RMR runs. Sometimes universities will offer them, otherwise google your area.

I hope they also told you what your body fat percentage was if they used the Bod Pod.

[gpoitras]

I hope they also told you what your body fat percentage was if they used the Bod Pod.

It wasn't with the Bod Pod. It was a fasted test, I laid in a dark room for 15 - 20 minutes while connected to a breathing apparatus covering mouth and nose, which measured the O2 in / CO2 out. The name of the software is escaping me now. The only data I gained from this RMR was the amount of calories required at rest and the percentage of fat vs. sugar my body relies on in a rested state.

[SumDumGoi]

It wasn't with the Bod Pod. It was a fasted test, I laid in a dark room for 15 - 20 minutes while connected to a breathing apparatus covering mouth and nose, which measured the O2 in / CO2 out. The name of the software is escaping me now. The only data I gained from this RMR was the amount of calories required at rest and the percentage of fat vs. sugar my body relies on in a rested state.

I misread what you were saying above. I thought you said that you had your RMR measured using a Bod Pod. But yeah, your resting RMR should have looked similar to the picture I posted above. However, they might not have had the hood and just placed a facemask over your mouth/nose to capture your air. They probably used the same metabolic cart to measure this as they did your VO2 max test. Usually it is a Parvomedics or Viasys/Sensormedics system, but there are a few other ones as well.

[gpoitras]

I misread what you were saying above. I thought you said that you had your RMR measured using a Bod Pod. But yeah, your resting RMR should have looked similar to the picture I posted above. However, they might not have had the hood and just placed a facemask over your mouth/nose to capture your air. They probably used the same metabolic cart to measure this as they did your VO2 max test. Usually it is a Parvomedics or Viasys/Sensormedics system, but there are a few other ones as well.

Yes, all you mention rings a bell. No hood, same cart and one of those names sounds familiar.

[midcoastking33]

How accurate is the Bodymedia Fit/Bodybugg?

More accurate than calculators, though probably not worth the money unless you are struggling to move the scale