Which of the following statements are CORRECT about body composition tests:
A Underwater weighing is measured by electrical impulses being sent through the water to get one’s body composition.
B The DEXA has less than 1% error rates, is the gold standard, and measures body composition and bone density.
C The Bod Pod is measured by water displacement to get your body composition.
D Body Mass Index is the most accurate ways for someone to measure their body composition.
E Skinfold tests are conducted in the same spots for everyone.
The correct answer and explanation is :
The correct answer is:
B. The DEXA has less than 1% error rates, is the gold standard, and measures body composition and bone density.
Explanation (Approx. 300 words):
Body composition tests are used to determine the percentages of fat, bone, water, and muscle in the human body. Understanding body composition is critical for evaluating health and fitness beyond what weight alone can indicate. Among the statements provided, option B is correct.
Dual-Energy X-ray Absorptiometry (DEXA or DXA) is widely considered the gold standard for measuring body composition. It is highly accurate, with an error margin of less than 1%, and it not only assesses fat and lean mass but also measures bone mineral density—making it invaluable for diagnosing osteoporosis and other bone conditions. The scan is non-invasive, quick, and provides a detailed breakdown of regional fat distribution (e.g., trunk vs. limbs).
Let’s address why the other statements are incorrect:
- A (Underwater weighing) is incorrect because it does not use electrical impulses. Instead, it involves water displacement based on Archimedes’ principle to estimate body density and composition.
- C (Bod Pod and water displacement) is incorrect because the Bod Pod uses air displacement, not water, to measure body volume and composition. It’s a non-invasive and relatively quick method often used in clinical and athletic settings.
- D (BMI accuracy) is incorrect because Body Mass Index (BMI) only takes height and weight into account. It does not measure fat percentage or muscle mass, making it an imprecise tool for assessing actual body composition, especially in muscular individuals.
- E (Skinfold test spots) is incorrect because skinfold measurements vary by sex, age, and protocol. Common sites differ between men and women to better estimate subcutaneous fat.
In summary, while several methods exist to assess body composition, DEXA stands out for its precision, reliability, and comprehensiveness.