Question

Decreased Basal Metabolic Rate is seen in:

• A. Obesity
• B. Hyperthyroidism
• C. Feeding
• D. Exercise

Hint:

Thyroid up, food and exercise all raise BMR; fat mass dilutes it.

Answer 1

The Correct Option is A

Step 1: BMR is set mainly by metabolically active lean tissue and is raised by anything that increases tissue metabolism.
Step 2: Hyperthyroidism raises BMR strongly because thyroid hormone increases oxygen consumption and heat production in almost all tissues. So option B raises, not lowers, BMR.
Step 3: Feeding raises energy expenditure through the specific dynamic action (thermic effect) of food, especially protein. Exercise increases muscle metabolism and oxygen demand, so it also raises metabolic rate. Options C and D both increase metabolism.
Step 4: In obesity the extra weight is largely fat, which is metabolically inactive. When BMR is expressed per unit body weight or per unit surface area, obese subjects show a relatively low value, so BMR per unit mass is decreased in obesity. Among the four choices, obesity is the condition linked with a decreased BMR.
Step 5: Therefore the answer is obesity.
Answer: Option A (Obesity).