Weight Loss Weight Loss Metabolism 2 — Questions and Answers
Question 1: What is 'metabolic flexibility' and why is it considered a health goal in weight management?
- The ability to lose weight rapidly
- The ability to efficiently switch between burning carbohydrates and fats as fuel (Correct answer)
- Having a very high BMR
- Tolerating large caloric surpluses without gaining weight
Correct answer: The ability to efficiently switch between burning carbohydrates and fats as fuel
Metabolic flexibility is the capacity to readily switch fuel sources—using carbohydrates or fats depending on availability and demand—which supports efficient energy use and healthy body composition.
Question 2: What happens to resting metabolic rate during prolonged caloric restriction, and why is it a challenge for weight loss maintenance?
- It increases to compensate for low intake
- It decreases through adaptive thermogenesis, reducing total calorie burn (Correct answer)
- It stays constant regardless of caloric intake
- It only changes with exercise, not diet
Correct answer: It decreases through adaptive thermogenesis, reducing total calorie burn
Prolonged caloric restriction triggers adaptive thermogenesis—the body reduces metabolic rate and energy expenditure to conserve resources, which slows weight loss over time.
Question 3: Which metabolic process converts excess carbohydrates and protein into fat for storage when caloric intake exceeds expenditure?
- Gluconeogenesis
- De novo lipogenesis (Correct answer)
- Ketogenesis
- Beta-oxidation
Correct answer: De novo lipogenesis
De novo lipogenesis is the metabolic pathway that synthesizes fatty acids from excess acetyl-CoA derived from surplus carbohydrates or protein, contributing to fat mass gain.
Question 4: What is the role of brown adipose tissue (BAT) in metabolism and weight management?
- BAT stores energy for long-term use like white fat
- BAT burns calories to generate heat, potentially aiding weight management (Correct answer)
- BAT is identical in function to white adipose tissue
- BAT is only found in infants and plays no role in adults
Correct answer: BAT burns calories to generate heat, potentially aiding weight management
Brown adipose tissue contains a high density of mitochondria and burns calories through thermogenesis (heat production), and activating BAT is an emerging target for obesity treatment.
Question 5: How does the gut microbiome influence metabolism and body weight according to emerging research?
- It has no established connection to body weight
- Gut bacteria affect calorie extraction from food, inflammation, and hormonal signals that regulate appetite (Correct answer)
- Only probiotics directly cause weight loss
- Gut bacteria only affect digestion, not weight
Correct answer: Gut bacteria affect calorie extraction from food, inflammation, and hormonal signals that regulate appetite
The composition of gut bacteria influences how many calories are extracted from food, systemic inflammation levels, and the production of hormones like GLP-1 that regulate appetite and metabolism.
Question 6: Which concept describes the body's tendency to return to a set body weight through hormonal and metabolic adjustments after weight loss?
- Caloric equilibrium
- Set point theory (Correct answer)
- Energy homeostasis plateau
- Metabolic baseline reset
Correct answer: Set point theory
Set point theory proposes that the body defends a particular weight range through adjustments in metabolism, hormone levels (especially leptin), and appetite that resist deviations from the set point.
Weight Loss Weight Loss Metabolism 2
What is 'metabolic flexibility' and why is it considered a health goal in weight management?