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Body Weight Homeostasis
➤ Mainly via body mass-dependent energy expenditure
➤ Individuals of male gender, increased height, increased muscle,
younger age, and/or obesity typically have higher metabolic rate
(MR).
➤ An increase in fat free mass may not only increase metabolic rate,
but may also increase hunger, which influences the nutritional
aspect of energy balance.
➤ Metabolic rate can be affected by climate (hotter environment
increases metabolic rate to cool the body; colder environment
increases metabolic rate through non-shivering thermogenesis to
warm the body).
➤ Beyond RMR, other common contributors to variances in energy
expenditure include NEAT, physical activity, and thermogenesis
of food.
Energy Expenditure: Components Overall
In individuals with light physical inactivity, components of total
energy expenditure:
• 70% resting MR
• 20% physical activity
• 10% diet-induced thermogenesis
In studies with purposefully sedentary behavior
a
, the coefficient of
variation for energy expenditure components are:
• Resting MR = 5–10%
• Physical exercise = 2%
• Diet-induced thermogenesis = 20%
b
a
NEAT also contributes to variances in energ y expenditure.
b
Whole foods generally generate higher diet-induced thermogenesis than ultra-processed food.
