TABLE 1.

Relevant terms and definitions related to energy metabolism

Term	Definition
Basal energy expenditure	Minimum energy required to maintain vital body functions. It represents ∼50–75% of total energy expenditure. It is measured under standard conditions, which include: a full night’s sleep in the metabolic unit, optimal fasting conditions for 12–14 h, laying down, remaining awake but motionless, abstaining from exercise for ≥12 h, and no physical exercise on the day of testing (8)
Resting energy expenditure	Energy required to support the body’s basic metabolic activities; resting energy expenditure can be 3–10% higher than basal energy expenditure
Activity energy expenditure	Energy expended to support physical activity (exercise and nonexercise) (9)
Diet-induced thermogenesis	Energy required after food intake for digestion, absorption, usage, and storage of nutrients (10)
Sleeping energy expenditure	Energy required to maintain vital body functions during sleep; it is 5–10% lower than basal energy expenditure (11)