def bmi_category(bmi):
    """ 
    Function to calculate bmi category 

    Parameters: 
        bmi (float): BMI value
        
    Returns: 
        bmi category (string) 
    """
    if bmi <= 18.4 :
        return "Underweight"
    elif bmi >=18.5 and bmi <= 24.9:
        return "Normal weight"
    elif bmi >=25 and bmi <= 29.9:
        return "Overweight"
    elif bmi >=30 and bmi <= 34.9:
        return "Moderately obese"
    elif bmi >= 35 and bmi <= 39.9:
        return "Severely obese"
    elif bmi > 40:
        return "Very severely obese"