Let’s revisit Jolene, who works as a registered nurse (RN) on the medical/surgical (MED) floor of a large hospital. An important part of Jolene’s job is patient education and on MED floor much of that education relates to healthy nutrition and body composition. Body composition attempts to quantify the relative amounts of different tissue types present in a person’s body, typically with emphasis on ensuring a healthy amounts of fat relative to other tissues. Body composition is just one of many measurable factors that health professionals use to evaluate a person’s overall health and assess risk for type II diabetes, cardiovascular disease, sleep apnea, osteoarthritis, osteoporosis, and other medical conditions.
Body Mass Index
The body mass index () attempts to categorize body composition using only height and as inputs. Health professionals like Jolene understand that the BMI can be useful when paired with other evaluations, but that it has many limitations when applied to individuals or very specific populations. For example, the extra caused by having more than average muscle can result in a false unhealthy weight categorization. . Additional methods for determining body composition include bioelectric impedance, anthropometric, DEXA scan, , and the skin fold method, which we will investigate in the following sections.
- "Measuring body composition." by J C K Wells and M S Fewtrell, U.S. National Library of Medicine, U.S. Department of Health and Human Services ↵
- "Assessing your weight and health risk" by National Heart, Lung, and Blood Institute, U.S. Department of Health and Human Services ↵
- "The Math of Fitness" by Eric Kim, A Healthy U, Andrews University ↵
Body Mass Index (BMI) is a person’s weight in kilograms divided by the square of height in meters. BMI can be used to screen for weight categories that may lead to health problems but it is not diagnostic of the body fatness or health of an individual
the force of gravity on on object, typically in reference to the force of gravity caused by Earth or another celestial body
a technique for measuring the mass per unit volume of a living person's body. It is a direct application of Archimedes' principle, that an object displaces its own volume of water