Endocrine Weight Loss Metabolic Rate and Energy Balance 1 — Questions and Answers
Question 1: Which component accounts for the largest portion of total daily energy expenditure in most adults?
- Thermic effect of food
- Physical activity
- Basal metabolic rate (Correct answer)
- Non-exercise activity thermogenesis
Correct answer: Basal metabolic rate
Basal metabolic rate (BMR) typically accounts for 60–75% of total daily energy expenditure in sedentary adults.
Question 2: Which hormone primarily regulates basal metabolic rate by controlling cellular oxygen consumption?
- Insulin
- Cortisol
- Thyroid hormone (Correct answer)
- Growth hormone
Correct answer: Thyroid hormone
Thyroid hormones (T3 and T4) are the principal regulators of basal metabolic rate by increasing cellular oxygen consumption and heat production.
Question 3: What term describes the increase in metabolic rate that occurs after eating a meal?
- Adaptive thermogenesis
- Thermic effect of food (Correct answer)
- Resting energy expenditure
- Post-absorptive state
Correct answer: Thermic effect of food
The thermic effect of food (diet-induced thermogenesis) is the increase in energy expenditure above basal levels following food ingestion.
Question 4: A patient on a prolonged calorie-restricted diet experiences a drop in metabolic rate beyond what is expected from lean mass loss. This is best described as:
- Insulin resistance
- Adaptive thermogenesis (Correct answer)
- Lipotoxicity
- Gluconeogenesis upregulation
Correct answer: Adaptive thermogenesis
Adaptive thermogenesis is the disproportionate reduction in metabolic rate that occurs during caloric restriction, partly driven by falling leptin and thyroid hormone levels.
Question 5: Which of the following best estimates resting energy expenditure in a clinical setting?
- Doubly-labeled water method
- Harris-Benedict equation (Correct answer)
- Skin-fold thickness measurement
- Bioelectrical impedance analysis
Correct answer: Harris-Benedict equation
The Harris-Benedict equation is commonly used clinically to estimate resting energy expenditure from height, weight, age, and sex.
Question 6: Non-exercise activity thermogenesis (NEAT) is best defined as:
- Calories burned during structured exercise sessions
- Energy expended during all physical activity except volitional exercise (Correct answer)
- The heat generated by brown adipose tissue
- Metabolic energy used during sleep
Correct answer: Energy expended during all physical activity except volitional exercise
NEAT encompasses all energy expended during activities of daily living excluding planned exercise, such as fidgeting, standing, and spontaneous movement.
Endocrine Weight Loss Metabolic Rate and Energy Balance 1
Which component accounts for the largest portion of total daily energy expenditure in most adults?