Why You Need a Body Composition Test for Successful Weight Loss

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A scale is an inadequate tool to gauge weight fat loss. A body composition test measures fat and lean tissue (everything besides fat) and tells you if you’re losing fat. Relying on a scale alone you could conclude you’re not making progress when you really are.

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Have you ever stepped on your bathroom scale only to be crushed by the number it comes up with? All the discipline you felt so proud of

…the exercise (especially if you loathe it)

…following your diet to perfection

…skipping that glass of wine the other night when you really really wanted it

and the scale says you weigh more than last time.

What the **BLEEP!**

The problem is a scale only measures body weight. When we say we want to lose weight we really mean we want to lose fat and gain muscle. Since muscle weighs more than fat using a scale is mostly an inaccurate tool to gauge success.

I’m not saying ditch the bathroom scale, as a matter of fact, get the most high-quality scale you can afford to have the most accurate and consistent readings.

But when your goal is body recomposition (lose fat, gain muscle) a body composition test is critical to your success.body composition test

What a body composition test tells you

A body composition test determines how much of your body is fat vs. lean tissue. Lean tissue includes your muscle, water, bone, and organs.

If you want to lose weight, your goal simply shouldn’t be pounds lost. An initial test will give you a baseline value of fat and lean tissue to help you set goals for both fat loss and muscle gain.

Subsequent tests, done every 4-6 weeks, will tell you what’s working (or not working) in your diet and fitness plan. A body composition test is essential especially if you have a significant amount of weight to lose.

Body Fat Rating for Women

Body Fat RatingBody Fat %Explanation
Risky (high body fat)>40%Ask your health care professional about how to safely decrease your body fat
Excess Fat30.1 - 40%Indicates an excess accumulation of fat
Moderately Lean22.1 - 30%Fat level is generally acceptable for good health
Lean18.1 - 22%Lower body fat levels than many people. This range is excellent for health & longevity
Ultra Lean15 - 18%Fat levels found in elite athletes
Risky (low body fat)<15%Ask your health care professional about how to safely increase your body fat
Source: American College of Sports Medicine

A DEXA body composition test provides a detailed map of your bone, fat, and other lean tissue.

Bone mass mapping can help identify a potential risk of osteoporosis. Visceral fat (fat stored in the abdomen around vital organs) mapping can identify long-term health risks such as chronic diseases.


Other reasons body composition tests are helpful

Have you heard of skinny fat?

A skinny fat person is in the normal range for weight and BMI but has more fat and not enough muscle mass than recommended for optimal health.

Equally important, as we age, our bodies naturally lose muscle mass and gain fat.

Too much fat and too little muscle puts us, particularly women, at risk for chronic disease and compromised mobility.

Women over 50 who have a higher fat mass, lower skeletal muscle mass, and poorer physical function have a higher prevalence of disability compared to men in the same situation. (Holmes et al., 2009)

Having a handle on body composition at any age is critical to optimal well-being.

Bod Pod Body Composition Test
Bod Pod Body Composition Test

The 5 best body composition tests

1. DEXA Scan

  • Uses dual-energy x-ray absorptiometry technology
  • Provides a map of fat, bone, and muscle mass in each region of the body
  • A technician review results with the subject
  • Highly accurate
  • Subject lies (fully clothed) on a table with the scanner overhead
  • Test time is 5 minutes; the entire appointment takes approximately 30 minutes
  • How to find it: do a Google search for DEXA scan near me
  • For more information visit https://www.dexafit.com/services/dexa-scan

2. Bod Pod

  • Uses air displacement plethysmograph (air puffed into the pod) technology with whole-body densitometry to determine body composition
  • Provides a table of fat and fat-free mass, total body mass, and thoracic gas volume (volume of air in the lungs)
  • A technician reviews the results with the subject
  • Highly accurate
  • Subjects wear snug fitting clothing (swimsuit or athletic wear)
  • Test time is 2 minutes; the entire appointment takes approximately 30 minutes
  • How to find it: do a Google search for Bod Pod near me
  • For more information visit https://www.cosmed.com/en/products/body-composition/bod-pod


3. Underwater Hydrostatic Weighing

  • Uses technology based on the Archimedes Principle of displacement theory
  • Subjects are weighed on dry land then submerged into a large water tank. Subjects sit on a special scale. The underwater weighing is repeated three times then averaged.
  • Provides a chart of fat and fat-free mass, total body mass
  • A technician reviews the results with the subject
  • Accuracy is dependent on the person administering the test and doing calculations correctly
  • Subjects wear a swimming suit
  • Entire appointment takes approximately 1 hour
  • How to find it: due to the expense of the equipment typically only universities and research institution have them
Body composition test
Skin Caliper

4. Skinfold Calipers

  • The most widely used and assessable of methods. Can be done by a trained technician or by individuals at home.
  • Technicians use a skin caliper tool to measure the thickness of skinfolds at specific body sites. A formula estimates body fat.
  • Only measures subcutaneous fat. A subject who holds more fat outside the tested areas could have a lower body fat reading.
  • Accuracy depends on the training and experience of the person performing the test and quality of the tool
  • It takes only a few minutes to perform
  • Inexpensive and easy to find experienced fitness trainers to complete the test. Skin caliper tools for home use can be also be purchased.
  • Not ideal for subjects who are obese or very thin

5. Bioelectrical Impedance Analysis (BIA)

  • Uses electrical current technology that sends currents through the body. Impedance is how fast the electric current travels through body tissue. Fat is an impedance to the current. The speed of the current is used to estimate fat-free body mass and estimate total body water and by difference with body weight, body fat.
  • Found in bathroom scales and more sophisticated scales found in gyms and healthcare offices
  • Accuracy is affected by the subject’s hydration level, meal and exercise times in relation to testing time
  • Accuracy depends on following a set protocol. Testing should be done at similar times and with the same conditions.
  • Consumer scales come in 2 electrodes (foot-to-foot) and 4 electrodes (feet, hands) models (more accurate).

A word of warning about Body Mass Index (BMI)

BMI isn’t the best measure of ideal weight.

BMI, the ratio of weight to height, doesn’t distinguish between bone, fat, and muscle. Hence, if a subject has large bones or a lot of muscle, their BMI would be skewed.

Instead of being disappointed by scale weight get a body composition test and have a more accurate picture of whether your weight fat loss plan is working.

And clean up your **bleeping** language!

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