DEXA Body Scan - Shed Fat, Not Weight
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I've had 2 DEXA scans after hearing they were the gold standard for body fat. They're not. DEXA scans are very good for bone density which is what they are designed for. DEXA scans are considered reliable for large populations but not reliable for individuals within the population. DEXA scans are also not reliable for tracking body fat changes. In my case, the DEXA scan said I had lost 10 pounds of muscle, even though I lifted weights and got stronger during the whole time in between scans. Unfortunately, there is no gold standard. Like other methods, the machines need to be calibrated. Going forward, I'm not going to worry about a body fat percentage. I'll focus on losing inches in the waist and hips and continue working out and dieting until I'm happy with how I look and feel.0
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atypicalsmith wrote: »It kills me to see how much money people are making off of people who want to lose weight, quit smoking, etc. Nicorette has been around for at least 35 years (which is the age of my son, when I decided to quit but didn't) and it's STILL around. If it worked, nobody would be smoking. Stop looking for a quick fix, people. Just DO IT!
Have you been drinking?0 -
atypicalsmith wrote: »It kills me to see how much money people are making off of people who want to lose weight, quit smoking, etc. Nicorette has been around for at least 35 years (which is the age of my son, when I decided to quit but didn't) and it's STILL around. If it worked, nobody would be smoking. Stop looking for a quick fix, people. Just DO IT!
psst.
I don't think you know what a dexa scan is.0 -
beertrollruss wrote: »I've had 2 DEXA scans after hearing they were the gold standard for body fat. They're not. DEXA scans are very good for bone density which is what they are designed for. DEXA scans are considered reliable for large populations but not reliable for individuals within the population. DEXA scans are also not reliable for tracking body fat changes. In my case, the DEXA scan said I had lost 10 pounds of muscle, even though I lifted weights and got stronger during the whole time in between scans. Unfortunately, there is no gold standard. Like other methods, the machines need to be calibrated. Going forward, I'm not going to worry about a body fat percentage. I'll focus on losing inches in the waist and hips and continue working out and dieting until I'm happy with how I look and feel.
Are you thinking of BMI? This is one very strange thread.
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The more I read MFP, the more I weep for the world's future.0
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_Terrapin_ wrote: »beertrollruss wrote: »I've had 2 DEXA scans after hearing they were the gold standard for body fat. They're not. DEXA scans are very good for bone density which is what they are designed for. DEXA scans are considered reliable for large populations but not reliable for individuals within the population. DEXA scans are also not reliable for tracking body fat changes. In my case, the DEXA scan said I had lost 10 pounds of muscle, even though I lifted weights and got stronger during the whole time in between scans. Unfortunately, there is no gold standard. Like other methods, the machines need to be calibrated. Going forward, I'm not going to worry about a body fat percentage. I'll focus on losing inches in the waist and hips and continue working out and dieting until I'm happy with how I look and feel.
Are you thinking of BMI? This is one very strange thread.
That's what I thought.
I think that's nearly word for word what I read about the bmi, being for populations not individuals.
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Merkavar, I think you'll find DEXA, Bod Pod, calipers, and over the counter scales measuring BF are all fairly close. Most people forget to to RTFM( Read The Fartin' Manual) and succumb to. . . ."it was't accurate, it can't be". I think I know of one MFP member who has used all 4 or 3 of the 4 and tracked them for a year. He was always within 1 or 2% of the other less expensive methods to measure your BF. BodPod he used every 3 months if I remember correctly due to cost. He also dropped a fair amount of weight in the process.0
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_Terrapin_ wrote: »beertrollruss wrote: »I've had 2 DEXA scans after hearing they were the gold standard for body fat. They're not. DEXA scans are very good for bone density which is what they are designed for. DEXA scans are considered reliable for large populations but not reliable for individuals within the population. DEXA scans are also not reliable for tracking body fat changes. In my case, the DEXA scan said I had lost 10 pounds of muscle, even though I lifted weights and got stronger during the whole time in between scans. Unfortunately, there is no gold standard. Like other methods, the machines need to be calibrated. Going forward, I'm not going to worry about a body fat percentage. I'll focus on losing inches in the waist and hips and continue working out and dieting until I'm happy with how I look and feel.
Are you thinking of BMI? This is one very strange thread.
Indeed. And being stronger doesn't mean you're building/ keeping muscle.
How much weight had you lost in total?0 -
Beertroll's right, DEXAs aren't that great for body fat measurements. They don't actually measure fat - they use models based on population averages, and while it's not an exact analogue to BMI, it's not a bad comparison.0
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Really great write up by the ETP group in regards to pros and cons of the different methods of getting body fat estimation if anyone was interested:
http://www.myfitnesspal.com/topics/show/830595-body-fat-estimation-methods0 -
Iron_Feline wrote: »_Terrapin_ wrote: »beertrollruss wrote: »I've had 2 DEXA scans after hearing they were the gold standard for body fat. They're not. DEXA scans are very good for bone density which is what they are designed for. DEXA scans are considered reliable for large populations but not reliable for individuals within the population. DEXA scans are also not reliable for tracking body fat changes. In my case, the DEXA scan said I had lost 10 pounds of muscle, even though I lifted weights and got stronger during the whole time in between scans. Unfortunately, there is no gold standard. Like other methods, the machines need to be calibrated. Going forward, I'm not going to worry about a body fat percentage. I'll focus on losing inches in the waist and hips and continue working out and dieting until I'm happy with how I look and feel.
Are you thinking of BMI? This is one very strange thread.
Indeed. And being stronger doesn't mean you're building/ keeping muscle.
How much weight had you lost in total?Iron_Feline wrote: »_Terrapin_ wrote: »beertrollruss wrote: »I've had 2 DEXA scans after hearing they were the gold standard for body fat. They're not. DEXA scans are very good for bone density which is what they are designed for. DEXA scans are considered reliable for large populations but not reliable for individuals within the population. DEXA scans are also not reliable for tracking body fat changes. In my case, the DEXA scan said I had lost 10 pounds of muscle, even though I lifted weights and got stronger during the whole time in between scans. Unfortunately, there is no gold standard. Like other methods, the machines need to be calibrated. Going forward, I'm not going to worry about a body fat percentage. I'll focus on losing inches in the waist and hips and continue working out and dieting until I'm happy with how I look and feel.
Are you thinking of BMI? This is one very strange thread.
Indeed. And being stronger doesn't mean you're building/ keeping muscle.
How much weight had you lost in total?
Not sure if this was for me?!? Was it?
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beertrollruss wrote: »I've had 2 DEXA scans after hearing they were the gold standard for body fat. They're not. DEXA scans are very good for bone density which is what they are designed for. DEXA scans are considered reliable for large populations but not reliable for individuals within the population. DEXA scans are also not reliable for tracking body fat changes. In my case, the DEXA scan said I had lost 10 pounds of muscle, even though I lifted weights and got stronger during the whole time in between scans. Unfortunately, there is no gold standard. Like other methods, the machines need to be calibrated. Going forward, I'm not going to worry about a body fat percentage. I'll focus on losing inches in the waist and hips and continue working out and dieting until I'm happy with how I look and feel.
How far apart were your scans? During that time, were you eating at a deficit? How large of a deficit? How about your protein macro? What was that set at?
If you were still in a deficit than eating sufficient protein and strength training helps minimize muscle mass loss, but it doesn't prevent it completely.
As IronFeline pointed out, as well, gaining strength =/= gaining/retaining muscle mass. You can definitely get much stronger without building additional muscle.0 -
I wouldn't mind getting one of these scans. But more when I get closer to my goal weight.
I hope I'm not losing muscle too much. I do cardio and some strength training and I keep putting my weights up every other week or so, suggests to me I'm gaining a little muscle at least.
According to my super "accurate" scale I have 30% body fat which if my math is correct, if I was to get to about 15-17% body fat I would be like 90kg which I think is above the healthy weight ranges I see.
Having a more accurate bf% would let me be more accurate in my goal.
I don't want to get down to the healthy weight range and find I lost 5-10kg of muscle to do it.
Whetherbeertrollruss wrote: »I've had 2 DEXA scans after hearing they were the gold standard for body fat. They're not. DEXA scans are very good for bone density which is what they are designed for. DEXA scans are considered reliable for large populations but not reliable for individuals within the population. DEXA scans are also not reliable for tracking body fat changes. In my case, the DEXA scan said I had lost 10 pounds of muscle, even though I lifted weights and got stronger during the whole time in between scans. Unfortunately, there is no gold standard. Like other methods, the machines need to be calibrated. Going forward, I'm not going to worry about a body fat percentage. I'll focus on losing inches in the waist and hips and continue working out and dieting until I'm happy with how I look and feel.
It's not so much a question of calibration but different machines use different models (2, 3, 4 compartment density models) to carry out calculations. They can be well calibrated and still give slight differences. Always try to use the same machine, set up by the sane technician.0 -
To answer pikaknight's questions, it was nine months in between scans. The scans were at two different places only because the first place was not available. I did eat at a deficit and I was 14 pounds lighter for the second scan. If I were to believe the second scan, I would have lost 4 pounds of fat and 10 pounds of muscle during that time while increasing my lifts 10-25% and consuming an average of 190 grams of protein during that time. I may have accepted losing 10 pounds of fat and 4 pounds of muscle, but not the other way around. A 10 pound difference on my 210 pound body is almost a 5% variability in readings. That's too much variability for me to trust either measurement.0
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beertrollruss wrote: »To answer pikaknight's questions, it was nine months in between scans. The scans were at two different places only because the first place was not available. I did eat at a deficit and I was 14 pounds lighter for the second scan. If I were to believe the second scan, I would have lost 4 pounds of fat and 10 pounds of muscle during that time while increasing my lifts 10-25% and consuming an average of 190 grams of protein during that time. I may have accepted losing 10 pounds of fat and 4 pounds of muscle, but not the other way around. A 10 pound difference on my 210 pound body is almost a 5% variability in readings. That's too much variability for me to trust either measurement.
So you have no baseline, just two completely independent measurements. You maximized, rather than minimize, variables.0 -
Merkavar:
This is what you get with a DEXA scan: http://www.bodycomp.ca/sample.html
By the looks of it, if you have a lot of "free" fat, eat sufficient protein for your lean body mass (let's call it a target of at least 0.7 per lb of LBM, with many advocating up to 1g per lb) , lift heavy weights, don't overdo the cardio and maintain a reasonable loss rate of no more than 1% per week (and/or eat at no greater deficit than 20% off your TDEE), you will have done everything you can to "spare" your lean body mass. And you will still lose some!
Having done it, did it give me any information that I couldn't live without? Given my original fat %, not really.
However, I found it darn informative and regret that I didn't do my first scan before I started losing weight!
re: scale based estimates:
My last scan was 32.8%. Mathematically I can only range between 34% (all subsequent weight loss was LBM) and 30.5% (all subsequent weight loss was fat). My scale has been saying 27% to 25%
Yes, I do realize that the "gold" standard is fairly silver.0 -
_Terrapin_ wrote: »Iron_Feline wrote: »_Terrapin_ wrote: »beertrollruss wrote: »I've had 2 DEXA scans after hearing they were the gold standard for body fat. They're not. DEXA scans are very good for bone density which is what they are designed for. DEXA scans are considered reliable for large populations but not reliable for individuals within the population. DEXA scans are also not reliable for tracking body fat changes. In my case, the DEXA scan said I had lost 10 pounds of muscle, even though I lifted weights and got stronger during the whole time in between scans. Unfortunately, there is no gold standard. Like other methods, the machines need to be calibrated. Going forward, I'm not going to worry about a body fat percentage. I'll focus on losing inches in the waist and hips and continue working out and dieting until I'm happy with how I look and feel.
Are you thinking of BMI? This is one very strange thread.
Indeed. And being stronger doesn't mean you're building/ keeping muscle.
How much weight had you lost in total?Iron_Feline wrote: »_Terrapin_ wrote: »beertrollruss wrote: »I've had 2 DEXA scans after hearing they were the gold standard for body fat. They're not. DEXA scans are very good for bone density which is what they are designed for. DEXA scans are considered reliable for large populations but not reliable for individuals within the population. DEXA scans are also not reliable for tracking body fat changes. In my case, the DEXA scan said I had lost 10 pounds of muscle, even though I lifted weights and got stronger during the whole time in between scans. Unfortunately, there is no gold standard. Like other methods, the machines need to be calibrated. Going forward, I'm not going to worry about a body fat percentage. I'll focus on losing inches in the waist and hips and continue working out and dieting until I'm happy with how I look and feel.
Are you thinking of BMI? This is one very strange thread.
Indeed. And being stronger doesn't mean you're building/ keeping muscle.
How much weight had you lost in total?
Not sure if this was for me?!? Was it?
No sorry. Quote fail0 -
Iron_Feline wrote: »_Terrapin_ wrote: »Iron_Feline wrote: »_Terrapin_ wrote: »beertrollruss wrote: »I've had 2 DEXA scans after hearing they were the gold standard for body fat. They're not. DEXA scans are very good for bone density which is what they are designed for. DEXA scans are considered reliable for large populations but not reliable for individuals within the population. DEXA scans are also not reliable for tracking body fat changes. In my case, the DEXA scan said I had lost 10 pounds of muscle, even though I lifted weights and got stronger during the whole time in between scans. Unfortunately, there is no gold standard. Like other methods, the machines need to be calibrated. Going forward, I'm not going to worry about a body fat percentage. I'll focus on losing inches in the waist and hips and continue working out and dieting until I'm happy with how I look and feel.
Are you thinking of BMI? This is one very strange thread.
Indeed. And being stronger doesn't mean you're building/ keeping muscle.
How much weight had you lost in total?Iron_Feline wrote: »_Terrapin_ wrote: »beertrollruss wrote: »I've had 2 DEXA scans after hearing they were the gold standard for body fat. They're not. DEXA scans are very good for bone density which is what they are designed for. DEXA scans are considered reliable for large populations but not reliable for individuals within the population. DEXA scans are also not reliable for tracking body fat changes. In my case, the DEXA scan said I had lost 10 pounds of muscle, even though I lifted weights and got stronger during the whole time in between scans. Unfortunately, there is no gold standard. Like other methods, the machines need to be calibrated. Going forward, I'm not going to worry about a body fat percentage. I'll focus on losing inches in the waist and hips and continue working out and dieting until I'm happy with how I look and feel.
Are you thinking of BMI? This is one very strange thread.
Indeed. And being stronger doesn't mean you're building/ keeping muscle.
How much weight had you lost in total?
Not sure if this was for me?!? Was it?
No sorry. Quote fail
Oh it's okay. I thought you meant the poster who has been lifting for a long time but didn't understand the difference between DEXA and BMI. I think Brian provided a spot on response for the poster.
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beertrollruss wrote: »To answer pikaknight's questions, it was nine months in between scans. The scans were at two different places only because the first place was not available. I did eat at a deficit and I was 14 pounds lighter for the second scan. If I were to believe the second scan, I would have lost 4 pounds of fat and 10 pounds of muscle during that time while increasing my lifts 10-25% and consuming an average of 190 grams of protein during that time. I may have accepted losing 10 pounds of fat and 4 pounds of muscle, but not the other way around. A 10 pound difference on my 210 pound body is almost a 5% variability in readings. That's too much variability for me to trust either measurement.
I think this is a good illustration of the 'it isn't accurate, no way this is even close' when in fact two different techs may have used two different set ups at the two different locations. The ego saying 'this can't be right' when in fact you need to choose one scan and repeat the scan at the same locale, use the same tech, and not be surprised when you've lost muscle mass eating in a deficit.
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