Final answer:
Bone density peaks at around 30 years of age and then starts to decline during middle adulthood, with females experiencing a more rapid decrease than males.
Step-by-step explanation:
Bone density peaks at around 30 years of age and then starts to decline during middle adulthood. In females, bone mass decreases more rapidly than in males, especially after menopause.
This is attributed to low levels of estrogen, which promotes bone growth.
The decrease in bone density can lead to osteoporosis, a condition characterized by weakened bones that are more prone to fractures.