Final answer:
Morbid obesity in the U.S. is diagnosed when an adult has a BMI of 40 or more. Recent data suggests that severe obesity affects an estimated 9.2% of the U.S. adult population.
Step-by-step explanation:
To be classified as morbidly obese, an adult must have a Body Mass Index (BMI) of 40 or more. The Centers for Disease Control and Prevention (CDC) define severe obesity or morbid obesity as a condition where a person's BMI is 40 kg/m² or higher, which carries significant health risks. According to a report by the National Center for Health Statistics, as of 2017-2018, the prevalence of severe obesity among adults in the United States is estimated to be lowering from previous percentages closer to 9.2%.