Morbidly obese jokes

Your mother is so fat that her BMI (Body Mass Index) exceeds 40, therefore classifying her as morbidly obese.

My friend was told by her doctor that she was morbidly obese.

As if she doesn't have enough on her plate.

A friend of mine used to be morbidly obese, but after lots of exercise and hard work... We were able to lift his coffin.