Converts a continuous BMI variable into a 3-level factor variable: Normal
weight if [-Inf, 25), Overweight if [25, 30), and Obese if
[30, Inf).
bmi3(x, labels = TRUE)Numeric vector of BMI values.
If TRUE, factor levels are labeled
"Normal weight", "Overweight", and "Obese"; if
FALSE, factor levels are [-Inf, 25), [25, 30), and
[30, Inf).
Factor variable with 3 levels.