In obesity energy calculations, which weight is sometimes used instead of actual weight?

• A. Actual body weight is always used
• B. Adjusted body weight is used to estimate energy needs in obese individuals
• C. Lean body weight is used
• D. Ideal body weight is used

Answer: (B)

In obesity energy calculations, the amount of weight that truly drives energy needs is not the total weight, because fat tissue contributes less to resting energy expenditure than lean tissue. This means using actual body weight can overestimate how many calories someone with obesity needs. To get a more accurate estimate, clinicians use an adjusted body weight, which reflects that only a portion of the excess weight is metabolically active.

A common way to compute it is: Adjusted body weight = ideal body weight + 0.25 × (actual weight − ideal weight). For example, if the ideal weight is 60 kg and the actual weight is 100 kg, the adjusted body weight would be 60 + 0.25 × 40 = 70 kg. Energy needs are then estimated based on 70 kg rather than 100 kg, reducing the risk of overfeeding.

Other options don’t fit as well because using actual weight can overstate needs in obesity, while lean body weight or ideal body weight alone either isn’t routinely practical to measure or would not accurately reflect the metabolic contribution of excess weight.