How does resting metabolic rate (RMR) differ from basal metabolic rate (BMR)?

• A. BMR is measured after eating, whereas RMR is measured after fasting.
• B. RMR is always lower than BMR because it excludes the energy used for digestion.
• C. BMR includes physical activity, while RMR does not.
• D. RMR is measured under less strict conditions than BMR and typically results in a slightly higher value.

Answer: (D)

Verified step by step guidance

1. Understand the definitions of Resting Metabolic Rate (RMR) and Basal Metabolic Rate (BMR). BMR is the amount of energy expended by the body to maintain basic physiological functions (e.g., breathing, circulation, and cellular processes) under strict conditions, such as complete rest, fasting, and a thermoneutral environment. RMR, on the other hand, is similar but measured under less strict conditions, such as after light activity or without a strict fasting requirement.
2. Recognize the key differences between RMR and BMR. RMR is typically measured in a more relaxed setting compared to BMR, which requires strict control of variables like fasting and complete rest. This makes RMR easier to measure in practical settings.
3. Understand why RMR is slightly higher than BMR. Since RMR is measured under less strict conditions, it may include additional energy expenditure from minor activities or digestion, which are excluded in BMR measurements.
4. Clarify misconceptions in the provided options. For example, BMR is not measured after eating—it requires fasting. Similarly, RMR is not always lower than BMR; it is typically higher due to the less strict conditions. Physical activity is excluded from both BMR and RMR measurements.
5. Conclude that the correct answer is: RMR is measured under less strict conditions than BMR and typically results in a slightly higher value. This reflects the practical differences in how these metabolic rates are assessed.