People are normally concerned about their BMI especially if they are concerned about the way that they look and their health. There are some people who may have a BMI that can be classified as obese while there are also some that may be classified as morbidly obese.
Those who are obese are more than overweight but those who are morbidly obese are usually 100 lbs heavier than their expected weight for their height. Those who have a BMI of 40 or higher will already be considered morbidly obese.
There are a lot of morbidly obese people who can barely move because they are already too heavy. Doing simple activities that will not be a problem for some people can be very problematic for them.