Summit Health offers Advanced Body Composition Analysis using a technique called DXA (Dual-energy X-ray Absorptiometry). This technique has been available for many years to assess bone density to test for osteoporosis and has recently been applied to body composition. DXA is now the gold standard for measuring body fat % and body composition.
Our Hologic Horizon A system ® provides very high-resolution images and is the only system that incorporates a whole-body composition reference database of thousands of US adults (NHANES) to allow comparison with other individuals of similar age, gender, and race.
Weight loss doesn’t always mean fat loss. With a beneficial weight loss and exercise plan, we want to keep calorie-burning muscle and lose only the fat. Knowing your body fat % and body composition helps you determine if your weight loss and muscle-building goals are realistic.
How does DXA body composition compare to other techniques?
DXA is superior in accuracy and detail to other methods for measuring body fat.
General body fat % Categories
| Description | Women | Men |
|---|---|---|
| Essential fat | 10-13% | 2-5% |
| Athletes | 14-20% | 6-13% |
| Fitness category | 21-24% | 14-17% |
| Average | 25-31% | 18-24% |
| Obese / Excess body fat | 32% or higher | 25% or higher |
Source: adapted from the American council on exercise.
*Essential fat (eFat) is the minimum amount of fat necessary for basic bodily functions. It is an essential component of cell membranes, bone marrow, cushioning for organs, and our temperature regulation system. eFat is generally higher in women and essential for ovulation.
The chart above does not take into account age or height. Your advanced body composition analysis provides far more accurate and meaningful information, taking into account your height and age, and compares you to individuals of a similar age, gender, and race.
• No other technique takes into account three compartments in the body- Bone, Fat, and Muscle.
• No other technique provides detailed measurements for seven segments in the body: each arm, each leg, trunk, central abdomen, and the head.
• DXA distinguishes between subcutaneous fat (under the skin) and higher risk visceral fat (surrounding the abdominal organs).
• DXA provides a measure of your bone density and risk for osteoporosis.
• DXA is excellent for tracking change. Images and numbers are stored centrally and when the scan is repeated, can show how your body has changed after a weight loss or exercise program.
Body Mass Index (BMI)
BMI uses height and weight. BMI measurement can penalize those with high muscle mass. Using BMI, a person with dense bone or bulky muscles can be classified as overweight.
Click here to see the BMI Chart
Skin Calipers
A skin caliper uses skinfold measurements, measures fat under the skin only, is very dependent on the skill and experience of the operator, and does not take into account body weight.
Body fat scales
Body fat scales use bioelectrical impedance and have low accuracy affected by the state of hydration, exercise, and eating. This method became popular owing to its ease of use, portability of the equipment, and relatively low cost compared to some of the other methods of body composition analysis. Bioelectrical impedance analysis (BIA) determines the electrical impedance or opposition to the flow of an electric current through body tissues which can then be used to calculate an estimate of total body water and body fat. Body fat measurements are lower when measurements are taken shortly after consumption of a meal, causing a variation between the highest and lowest readings of body fat percentage taken throughout the day of up to 9.9%. Moderate exercise before measurements leads to an overestimation of fat-free mass and an underestimation of body fat percentage due to reduced impedance. For example, moderate-intensity exercise for 90–120 minutes before BIA measurements cause nearly a 12 kg overestimation of fat-free mass, i.e. body fat is significantly underestimated.
Underwater (Hydrostatic) Weighing
Underwater (hydrostatic) weighing uses water displacement during which a person is dunked into a water tank. This was the previous bench-mark method for measuring body fat. Underwater weighing does not account for differences in bone density and is often inaccurate due to the fact that few people can completely exhale all air from their lungs prior to being submerged in the water tank. Therefore, if you are a person with denser bones (typically athletes) or brittle bones (osteoporosis), the accuracy of the body fat % is far superior with DXA.
Bod Pod
Bod pod uses air displacement in a chamber and is very dependent on the state of hydration.
You will be exposed to a small amount of radiation during a DXA body composition scan, similar to or less than
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- • An airplane flight from Portland to Denver
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- • Standing outside for 3 hours at sea level
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- • 1/20th of a chest X-ray
- • Dental X-rays
In fact, the exposure is so low that our technicians do not need to leave the room during the scan.
Why get a Body Composition Analysis?
Body fat % is the most accurate measure of obesity risk and an excellent gauge of overall health. DXA Body Composition Analysis gives you a precise, reliable and non-invasive measure of your body fat %. If you are overweight, it is vital to choose an effective and sustainable weight loss plan. Weight loss doesn’t always mean fat loss. With a beneficial weight loss and exercise plan, we want to keep calorie-burning muscle and lose only the fat. Knowing your body fat % and body composition helps you determine if your weight loss and muscle-building goals are realistic.
Worldwide obesity has increased at an alarming rate, making the demand for an accurate body composition analysis greater than it has ever been.
More than one-third of adults and 1 in 6 children and adolescents in the US are obese.
Obesity increases the risk for heart attack, stroke, diabetes, certain cancers, sleep apnea, osteoarthritis, infertility.
Persons who are obese have medical costs that are $1,429 per year higher than those of normal weight.
No state has an obesity rate less than 15%, the national goal.
Prevalence of Obesity Among U.S. Adults by State 2013
Source: Behavioral Risk Factor Surveillance Systems, CDC
Immediate Advanced Body Composition Analysis report contains numerical measurements and digital color images.
The 3 different tissues measured appear as different colors on a 2D image.
Because this is a 2D image, where there is a combination of tissue types, there will be a blend of these colors.
The first time you have a scan, the report will tell you:
• Your Body fat % with comparison to the reference population
• Where you store fat
• Your total and lean tissue (muscle)
• Your regional muscle mass and muscle symmetry
• Your total bone density
With subsequent scans, you will be able to identify precisely how your body changed after diet and/or exercise program or other intervention.
• Did you lose fat?
• Did you gain muscle?
• Did all those squats in the gym increase your leg muscle mass?
We generate our patient-friendly supplementary report to translate the data from your scan an individual action plan.
• Ideal body weight
• Risk assessment for bone density, total and central abdominal fat%
• Resting metabolic rate
• Suggested target fat weight loss
• Suggested calorie intake to attain ideal body weight based upon resting metabolic rate
• Suggested calorie intake to attain ideal body weight based upon activities
• Suggested structured exercise energy expenditure goal
• Monitor fat % before and after weight loss diet, medications, surgery
• Monitor muscle mass before and after an exercise program
• Provides an overall measure of the bone density of all of the bones in your body. If this is low, this may indicate osteoporosis, and you should consult your physician to have a comprehensive, medical DXA bone density scan.
• Used to evaluate muscle atrophy after injury and recovery following rehab in athletes
• Used in research studies to evaluate cardiovascular disease risk, effects of growth hormone treatment on muscle mass, monitor fat distribution in lipodystrophy syndromes, evaluation of muscle wasting in muscular dystrophies
Your DXA Advanced Body Composition Analysis results will consist of:
- An immediate Advanced Body Composition Analysis report
Advanced Body Composition Analysis report 3 different tissues measured appear as different colors on a 2D image.
Because this is a 2D image, where there is a combination of tissue types, there will be a blend of these colors.
The first time you have a scan, the report will tell you:
• Your Body fat % with comparison to the reference population
• Regional body fat %
• Central abdominal fat (Visceral adipose tissue)
• Your total lean tissue (muscle)
• Your regional muscle mass and muscle symmetry
• Your total bone density
With subsequent scans, you will be able to identify precisely how your body changed after diet and/or exercise program or other intervention.
• Did you lose fat?
• Did you gain muscle?
• Did all those squats in the gym increase your leg muscle mass?
Sample Report:
Guide on how to interpret your DXA body composition report
Sample Advanced Body Composition Guide:
Preparation:
Do NOT exercise vigorously or eat for 2 hours prior to the test.
Do NOT take calcium supplements on the day of testing.
Repeat scans should be at similar times of day, wearing similar clothing as prior tests.
Should NOT have this test if:
- Currently pregnant
- Within 1 week of having a test that involves barium, oral or intravenous contrast material (such as a CT or MRI), a radioisotope injection, as these can interfere with the accuracy of the test.
- You exceed the table weight limit of 500lbs
During the exam:
- Report to Area 1, at the Summit Health Eastside Clinic (1501 NE Medical Center Drive)
- You should wear lightweight, loose-fitting clothes (eg. exercise clothes). Avoid clothes that are tight at the waist as this may distort the images.
- No metal on clothing – check zippers, fasteners, belts, underwire bra
- Remove all jewelry, hair accessories, and other removable metal objects.
- Irremovable piercings, pins, screws, prosthetic joints are safe to scan but should be stated to the technologist. Metal will show up as a dense, white spot and result in an extremely small error and remain constant for repeat tests.
- The technologist will position you fully dressed, laying on your back on a comfortable open-air platform table. You will need to lay still while the scanner passes over your body – this is completely painless and takes about 6 minutes.
After the exam:
- You can return to your normal activities immediately
- You will receive an Immediate Advanced Body Composition Analysis report with numerical measurements and digital color images, and a general guide on how to interpret a DXA body composition report
Your advanced body composition analysis Supplementary report will translate the facts and figures generated by the DXA scan to a suggested action plan.
We will use the data from your scan to calculate your:
- Ideal Bodyweight
- Risk assessment for bone density, total and central abdominal fat percentage
- Resting metabolic rate (RMR)
- Suggested target fat weight loss
- Suggested calorie intake to attain ideal body weight based upon RMR
- Suggested structured exercise energy expenditure goal