The Harris-Benedict Equation is used to estimate:

Appeared in: BTSC Staff Nurse 31 July-2025

Explanation

The Harris-Benedict equation is a widely used method to estimate the Basal Metabolic Rate (BMR).
BMR represents the minimum amount of energy (calories) the body needs to perform its most basic, life-sustaining functions while at rest.
The calculation uses a person's gender, weight, height, and age as variables to determine their resting energy expenditure.

Option A: Body Mass Index (BMI) is a measure of body fat relative to height and weight, used to categorize an individual's weight status (e.g., underweight, normal, overweight). It does not estimate energy expenditure.
Option B: Body Surface Area (BSA) is a measurement of the total surface of the human body. It is not a measure of metabolic rate.
Option D: Ejection Fraction (EF) is a key measurement in cardiology that assesses how well the heart is pumping blood. It has no direct relation to metabolic rate.

Clinical Relevance

Nursing practice connection: This is primarily an exam-oriented knowledge point with limited direct bedside application, so retain Application of the Harris-Benedict Equation as background academic context rather than a clinical decision trigger.
Nurses use BMR estimates as a foundation for nutritional assessments and to create individualized diet plans that meet patients' energy needs.
Understanding a patient's BMR is critical for managing nutritional support in various clinical settings, including for patients with obesity, malnutrition, severe burns, or those who are critically ill.
What if? If a patient has a high fever, their BMR increases by approximately 7% for each degree Fahrenheit rise in body temperature. A nurse would need to account for this increased metabolic demand by providing a higher caloric intake to prevent catabolism and support recovery.

How to Approach the Question

This is a factual recall question that tests your knowledge of common clinical formulas.
First, identify the key term in the question stem: 'Harris-Benedict Equation'.
Access your knowledge base regarding nutritional assessment tools. Recall that this specific equation relates to energy.
Systematically evaluate each option. Differentiate between measures of body composition (BMI), drug dosing (BSA), cardiac function (Ejection Fraction), and energy expenditure (BMR).
Conclude that the Harris-Benedict Equation is specifically designed to estimate Basal Metabolic Rate (BMR), which is a measure of resting energy expenditure.

Concept Tested & Keywords

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E6 Nutrition Monika Sharma 3e p. 75-77

E6 textbook of Applied Biochemistry and Nutrition & DieteticsHarbans Lal (pp 26-464 of 479) p. 262-264

E6 Textbook of Biochemistry for medical StudentsDM Vasudevan Part 2 — Subpart A (pp 1-239 of 478) p. 184-186

Practise the full BTSC Staff Nurse 31 July-2025

Attempt every question from this paper in a timed mock, then review the full solution for each one.