Below is an instruction from Human. Write a response.
    ### Instruction:
    Who is at risk for Obesity Hypoventilation Syndrome? ?
    ### Response:
    People who are obese are at risk for obesity hypoventilation syndrome (OHS). "Obesity" refers to having too much body fat. People who are obese have body weight that's greater than what is considered healthy for a certain height.
                
The most useful measure of obesity is body mass index (BMI).
    