In which developmental period is basal metabolic rate highest?

In which developmental period is basal metabolic rate highest?

• A. Infancy
• B. Toddler
• C. School age
• D. Adolescence

Answer: (A)

Basal metabolic rate reflects the energy the body needs at rest to maintain basic functions. Infancy involves the fastest growth and brain development, with tissues rapidly expanding and organs maturing. This high growth activity drives a large energy demand even when the infant is not active, and the energy cost per unit of body weight is the highest during this period. As children age, growth slows and body mass increases, so the resting energy requirement per kilogram declines. Puberty in adolescence does raise metabolic needs a bit due to increased lean mass and hormones, but on a per‑weight basis it doesn’t reach infancy levels. So the highest basal metabolic rate occurs during infancy.

Basal metabolic rate reflects the energy the body needs at rest to maintain basic functions. Infancy involves the fastest growth and brain development, with tissues rapidly expanding and organs maturing. This high growth activity drives a large energy demand even when the infant is not active, and the energy cost per unit of body weight is the highest during this period. As children age, growth slows and body mass increases, so the resting energy requirement per kilogram declines. Puberty in adolescence does raise metabolic needs a bit due to increased lean mass and hormones, but on a per‑weight basis it doesn’t reach infancy levels. So the highest basal metabolic rate occurs during infancy.