To define obesity on the basis of BMI, it should be-
**Core Concept**
Obesity is a complex medical condition characterized by an excess amount of body fat, which can increase the risk of various health problems. The body mass index (BMI) is a widely used metric to categorize obesity based on an individual's weight and height.
**Why the Correct Answer is Right**
BMI is calculated as weight in kilograms divided by the square of height in meters (kg/m^2). According to the World Health Organization (WHO), obesity is defined as a BMI of 30 or higher. This cutoff value is used to differentiate between overweight (BMI 25-29.9) and obese individuals. The BMI calculation takes into account the distribution of body fat, which is not directly measured.
**Why Each Wrong Option is Incorrect**
**Option A:** BMI values less than 18.5 are used to define underweight, not obesity.
**Option B:** BMI values between 18.5 and 24.9 are used to define normal weight, not obesity.
**Option C:** BMI values between 25 and 29.9 are used to define overweight, not obesity.
**Clinical Pearl / High-Yield Fact**
It is essential to note that BMI has limitations, as it does not account for muscle mass or body composition. For example, athletes with a high muscle mass may have a high BMI without being obese. Therefore, BMI should be used in conjunction with other measurements, such as waist circumference and body fat percentage, to assess obesity.
**Correct Answer: C. A BMI of 30 or higher.**