Being obese means that one is severely overweight, leading to higher health risks; typically, 20% or more above recommended weight, or a BMI of above 30 would be considered obese. It is defined as over 20%, not 30.
The answer is true because if your body weight is at least 20% over what it should be, you are considered obese. This applies to BMI(Body Mass Index) as well. If your BMI is 30 over what it should be, you are considered obese.