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Old 08-12-2010, 11:13 AM   #19
Brad Gibbs
New Member
Join Date: Aug 2010
Posts: 11

Originally Posted by Derek Weaver View Post
If you got a question related to your situation, ask away.
*** NOTE: I cross-posted this to the Rapid Fat Loss forum on Lyle McDonald's site. I feel like the quality of the responses and the knowledge on this forum is better, despite the fact that the other site is a better fit for the subject matter ***

I had a DEXA scan on July 21. I knew I wasn't in great shape and I needed to do something about it. That was supposed to be the before picture -- but it became more of a wake-up call / reality check.

I was told by the operator who performed the DEXA (now DXA?) scan that body fat percentage readings by DEXA are significantly higher than readings produced by calipers or impedance (at least impedance measurement on a home scale).

She said that she's only seen three sub-10% readings in her 6 years, and one of them was a guy with a rare wasting disease who couldn't keep weight on. She said most competitive athletes (cyclists, marathoners and tri-athletes) she sees are 10-15%. Most "fit" people (her term, not sure what it means) are 15-20% and average is low- to mid-twenties. Does this ring true with anyone else?

My reading was 27.2%. She assured me that that's on the high side of normal. I'm trying to confirm that by looking at various sources in books and around the Internet.

I've seen posts on the Body Recomposition forums stating that DEXA does result in higher numbers than other methods, but also that it's the most accurate.

On page 31 of RFL, there's a chart that puts people in category 1, 2 or 3, based on body fat percentages. So, my question (finally) is: Does my 27.2% DEXA body fat put me in Category 3? Or, should some kind of adjustment be made because that measurement was attained using DEXA? I've tried using the Accu Measure, but I can't get anything close to repeatable results. My body scale (Withings) is a cool idea, but, I can make it go up or down 3% within 15 minutes, without drinking, eating or voiding (weighing my self immediately after voiding, first thing in the morning vs. 15 minutes later). And, it only measures the lower body. So, I don't feel like I can rely on that, either. It gives me readings between 20% and 23%.

Also, as a follow-on, can anyone point me to some table of averages for body fat percentages measured by DEXA? Since it's an opt-in program (that isn't inexpensive), there's some self-selection process there and I think the tendency is for leaner-than-average people to have the test. As a result, the official data is skewed toward a thinner population. I'm hoping to find some relative comparison between a DEXA result and the general populace so I can accurately assess just how bad the before picture is.

Based on information I've seen around the web, I think I'm aiming for 10-14% fat. I'm approaching 38 and I have no plans to enter any powerlifting or bodybuilding competitions -- I just want to be healthier and feel more comfortable in my own skin. So, I'm trying to get a sense of whether I need to lose 13%+ (27% - 14%) to enter that comfortable range, or some amount less than that. Without knowing what I've seen, I know there's no way any of you can answer that, but, that's where I'm coming from.

Thanks for any input.

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