Obesity occurs when someone is what percentage above the appropriate weight?

Obesity is classified when an individual's body weight is significantly above the appropriate weight for their height and body composition, typically measured using the Body Mass Index (BMI). A common threshold for defining obesity is being at least 30% above the appropriate weight. This percentage indicates that the excess weight is substantial enough to increase the risk of various health complications, such as heart disease, diabetes, and other metabolic disorders.

The other options reference lower percentages that fall short of this classification threshold. For example, being 20% or 25% above the appropriate weight may denote being overweight but not yet categorized as obese. Thus, the correct answer reflects the standard medical definition for obesity, which is defined as an increase of 30% or more above the healthy weight range.