Endocrine Weight Loss Metabolic Rate and Energy Balance 2

Question 1

Which substrate contributes most to energy expenditure during low-intensity, steady-state aerobic exercise?

Accepted Answer

Fat

Answer

During low-intensity aerobic exercise (below ~60% VO2max), fat oxidation is the predominant energy source.

Question 2

The first law of thermodynamics applied to weight management states that:

Accepted Answer

Energy balance equals energy intake minus energy expenditure

Answer

The first law of thermodynamics dictates that energy cannot be created or destroyed; weight change reflects the net difference between energy intake and total energy expenditure.

Question 3

Which of the following factors most significantly reduces resting metabolic rate in older adults?

Accepted Answer

Loss of skeletal muscle mass (sarcopenia)

Answer

Sarcopenia (age-related skeletal muscle loss) is the primary driver of declining resting metabolic rate in older adults because muscle is metabolically active tissue.

Question 4

Brown adipose tissue (BAT) contributes to energy expenditure primarily through:

Accepted Answer

Uncoupling of oxidative phosphorylation via UCP-1

Answer

BAT generates heat by uncoupling the proton gradient in the mitochondrial inner membrane from ATP synthesis via uncoupling protein-1 (UCP-1), dissipating energy as heat.

Question 5

A caloric deficit of approximately how many kilocalories is traditionally considered necessary to lose one pound of body fat?

Accepted Answer

3,500 kcal

Answer

The widely used estimate is that a cumulative deficit of approximately 3,500 kcal corresponds to one pound of fat loss, though individual variation exists.

Endocrine Weight Loss Practice Test

Endocrine Weight Loss Practice Test

Endocrine Weight Loss Metabolic Rate and Energy Balance 2