We already used morbidly obese.    Classification BMI     Underweight <19   Ideal BMI 19-25   Overweight 25-30   Obese >30   Severely Obese >35   Morbidly Obese >40   Super Obese >50    source If people start getting too much fatter, we'll have to add Mega Obese, Hyper Obese, Giga Obese, etc.