Activity 3B: Hy-Density: An Exploration of Hydrodensitometry

Hydrodensitometry is the “Gold Standard” for determining body composition. In our time, one of the greatest health risks facing people is obesity. However, defining obesity is not as simple as it might seem. Many people would say that standing on the bathroom scales and reading the number is the way they measure obesity. What makes the issue more complex than that is the fact that two people weighing 200 pounds may differ greatly in their body composition and overall health. One may be a body builder, in whom much of his/her body weight is due to muscle, while the other may be a “couch potato” in whom much of his/her body weight is fat tissue. It is really a matter of how much fat and fat-free mass they have. When the percentage of fat increases and fat-free mass decreases a person can become obese. This activity is not focused on obesity per se, but on body composition and how it can be measured. Knowing that most teachers do not have an underwater weighing tank in their room and that there are sensitivity issues involved in teaching adolescents about body composition, a simpler way for students to learn about the method that is considered one of the more accurate methods for determining fat and fat-free masses in an individual. 

Scientific process, buoyancy, homogeneous, heterogeneous, mass, volume, weight, density, fat tissue, muscle tissue, body composition, obesity


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Activity Code: 
Unit Reference: 
Corpulosity: A Study of Obesity
Lesson Reference: 
Lesson 3: Fat: Who Says? (Measuring Obesity)