Body mass index (BMI) is a better indicator of obesity than body weight because BMI is

• A. the ratio of height to weight
• B. the ratio of weight to height
• C. determined by indirect calorimetry
• D. determined by direct calorimetry

Answer: (A)

BMI adjusts weight for height to reflect body size, not just total mass. It is calculated as weight in kilograms divided by height in meters squared, so it scales weight relative to how tall someone is. This normalization helps distinguish excess fat from simply being tall or muscular, since tall people naturally weigh more even if they don’t have extra fat. Body weight alone can be misleading for obesity because it doesn’t account for height or body composition, whereas BMI provides a better proxy by relating weight to height squared. The other concepts referenced—calorimetry methods—measure energy expenditure, not how BMI is defined.