Which equation is used to estimate calorie needs in older adults, and what adjustment is added for physical activity?

• A. Harris-Benedict equation with +5-15% PA
• B. Mifflin St. Jeor equation with +10-30% PA
• C. Cunningham equation with +20-40% PA
• D. Penn State equation with +5-10% PA

Answer: (B)

Estimating calorie needs in older adults starts with calculating resting energy expenditure using the Mifflin-St Jeor equation, which is based on current data and uses weight, height, age, and sex to estimate how many calories the body needs at rest. To turn that into daily energy needs, you adjust for physical activity. In older adults, a practical adjustment adds about 10–30% to the resting estimate, depending on how active the person is. This approach captures the activity component without over- or underestimating energy needs across a range of activity levels.

Other equations exist, but they’re less appropriate here: Harris-Benedict is older and can overestimate energy needs in many populations; Cunningham relies on lean body mass and is often used in specific groups; Penn State is tailored for critically ill patients. The combination of Mifflin-St Jeor plus a moderate activity adjustment aligns best with typical older adult populations.