Resting Energy Requirement Calculator

Resting Energy Expenditure Formula:

\[ REE = k \times W \]

Resting Energy Expenditure:

kcal/day

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1. What is Resting Energy Expenditure (REE)?

Definition: REE is the amount of energy required by the body at complete rest to maintain basic physiological functions like breathing, circulation, and cell production.

Purpose: This calculator estimates daily caloric needs for individuals at complete rest, useful for nutrition planning and medical assessments.

2. How Does the Calculator Work?

The calculator uses the formula:

\[ REE = k \times W \]

Where:

\( REE \) — Resting energy expenditure (kcal/day)
\( k \) — Constant (typically 10-20 kcal/kg/day)
\( W \) — Body weight (kg)

Explanation: The body weight is multiplied by a constant factor that represents the energy expenditure per kilogram of body weight.

3. Importance of REE Calculation

Details: Understanding REE helps in creating appropriate nutrition plans, managing weight, and determining caloric needs for patients with specific medical conditions.

4. Using the Calculator

Tips: Enter body weight in kilograms and select an appropriate constant (default 15 kcal/kg/day). The constant typically ranges between 10-20 depending on factors like age, sex, and body composition.

5. Frequently Asked Questions (FAQ)

Q1: What's the difference between REE and BMR?
A: REE (Resting Energy Expenditure) and BMR (Basal Metabolic Rate) are similar but measured under slightly different conditions. REE is typically about 10% higher than BMR.

Q2: How do I choose the right constant (k)?
A: Use lower values (10-12) for elderly or sedentary individuals, average values (13-15) for most adults, and higher values (16-20) for athletes or those with high muscle mass.

Q3: Does this account for activity level?
A: No, this calculates only resting expenditure. For total daily energy expenditure, multiply REE by an activity factor (1.2-2.5).

Q4: Why is weight in kg?
A: The formula is based on metric measurements. To convert from pounds, divide by 2.205.

Q5: How accurate is this simple formula?
A: While simple, it provides a reasonable estimate. More accurate methods include indirect calorimetry or Harris-Benedict equation.