A morbidly obese person is someone who is very overweight to the point that it can often cause a shorter lifespan and health problems.
According to the BMI scale: Underweight: < 18.5
Ideal: 18.5-24.9
Overweight: 25-29.9
Obese: 30-39.9
Morbidly obese: 40-49.9
Super morbidly obese: 50+
BMI (Body Mass Index) is a calculation of height and weight.