From current WHO data
Yes - I realize BMI is an imperfect indicator, but it is easy to gather and is a good enough proxy for population obesity. If you are extremely muscular your BMI is artifically high, if you have very little muscle it is artifically low. It is very possible to be "overweight" and in good physical shape, although it is less likely than being in good shape if your BMI is in the "average" range.
The defintions are:
underweight: BMI less than 18.5
normal: BMI between 18.5 and 24.99
pre-obese: BMI between 25.0 and 29.99
obese: BMI over 30.0
These days so many are obese that the category is broken down as medical attention is usually warranted.
obese class I: BMI between 30.0 and 34.99
obese class II: BMI between 35.0 and 39.99
obese class III: BMI over 40.0