In assessing weight-related health risk, one problem with using body mass index (BMI) is that it:

• A. Does not distinguish between fat mass and lean (muscle) mass
• B. Directly measures body fat percentage with high precision in all individuals
• C. Is unaffected by height because it uses only body weight in its calculation
• D. Accounts for where body fat is distributed (e.g., abdominal vs. hip) without any additional measures

Answer: (A)

Verified step by step guidance

1. Understand what Body Mass Index (BMI) is: BMI is a numerical value calculated from a person's weight and height, commonly used to categorize underweight, normal weight, overweight, and obesity.
2. Recall the formula for BMI, which is given by \(\text{BMI} = \frac{\text{weight (kg)}}{\text{height (m)}^2}\), showing that it uses both weight and height in its calculation.
3. Recognize that BMI does not differentiate between types of body mass, meaning it treats muscle mass and fat mass the same, which can lead to misleading assessments in muscular individuals.
4. Note that BMI does not provide information about body fat distribution, such as whether fat is stored around the abdomen or hips, which is important for assessing health risks.
5. Conclude that the main limitation of BMI in assessing weight-related health risk is that it does not distinguish between fat mass and lean (muscle) mass.