Lecture #24 Flashcards
What is Basal Metabolic Rate (BMR) and how is it determined?
BMR refers to the energy expenditure necessary to sustain life’s biochemical processes.
It is measured in a rested and relaxed state, at thermoneutrality, and after 8-12 hours of fasting. It accounts for approximately 60-75% of total daily energy expenditure (TDEE), although athletes may have a lower BMR.
How does increasing muscle mass affect BMR?
Increasing muscle mass has a relatively small effect on BMR; gaining 1kg of muscle increases BMR by only 13kcal.
Skeletal muscle BMR can be modified through voluntary contraction and relaxation.
What is the Thermic Effect of Food (TEF) or Diet-Induced Thermogenesis (DIT), and what are its components?
TEF/DIT refers to the increase in energy expenditure following a meal, accounting for 10-15% of TDEE. It has two components:
“Obligatory”: Energy expended for digestion, absorption, and storage of nutrients.
“Facultative”: Involves the activation of the sympathetic nervous system and thermogenesis.
What is adaptive thermogenesis and how does it affect energy expenditure?
Adaptive thermogenesis is the energy dissipated as heat in response to environmental changes or dietary alterations.
It includes responses like shivering in the cold and metabolic rate adjustments when food intake is less than energy spent.
This adaptive response is also triggered by the amount of food available to the body
It is a biological mechanism that can make maintaining weight loss challenging.
Lean body mass (LBM):
which is the body mass minus fat, are significant predictors of whole-body energy expenditure.
How does adipose tissue regulate energy expenditure, given that the metabolic rate of a fat cell is very low?
While the metabolic rate of a fat cell is low, adipose tissue (White Adipose Tissue or WAT) plays a crucial role in determining overall metabolic rate. Adipose tissue can affect energy expenditure through various mechanisms including the release of hormones that influence metabolism, energy storage, and the insulation and padding of the body.
