Body fat and Body mass index (BMI) of AIS athletes

Use this diagram to introduce the idea that a simple regression (e.g. of body fat as a linear function of BMI) may ignore other available information that could help with predicting the response.

The crosses in the scatterplot of body fat against BMI are dynamically linked to a table with other variables about the individuals — click on any cross to see the sex, sport, etc. of that athlete.

The relationship between body fat and BMI is not strong. Investigate a few of the more 'extreme' athletes on the scatterplot and ask whether their other variables might help to explain why they have their percentage body fat.

Data were collected from a sample of 202 elite athletes who were in training at the Australian Institute of Sport. The variables used on this page are:

Note that BMI is often used as an indicator of obesity — an adult with BMI of 30 or above is usually classified as obese.